Labral Gracilis Tendon Allograft Reconstruction and Cartilage Regeneration Scaffold for an Uncontained Acetabular Cartilage Defect of the Hip Laurel E. MacInnis, B.Sc.H.K., B.Sc.P.A., C.C.P.A., Ahmed Al Hussain, M.D., Catherine Coady, M.D., F.R.C.S.C., and Ivan H. Wong, M.D., M.A.C.M., F.R.C.S.C., Dip. Sports Medicine
Abstract: Hip cartilage injuries are very common, with rates as high as 50% having been reported in some series; abnormal femoral acetabular contact can result in a full-thickness cartilage defect or labral lesion. The prevalence of labral lesions can be as high as 55%. This Technical Note describes an arthroscopic technique to reconstruct an uncontained, fullthickness, focal cartilage defect of the acetabulum, with reconstruction of the missing labrum using a gracilis allograft and use of a biological liquid scaffold for cartilage reconstruction. Capsulotomy, acetabuloplasty, and microfracture with marrow bleeding should be performed simultaneously with the gracilis allograft preparation. The graft is inserted and anchored to reconstruct the missing labrum and to re-create a contained defect. Suction and drying of the joint surfaces are performed while the mixture of BST-CarGel (Piramal Healthcare, Laval, Quebec, Canada) and blood is prepared. A drop-by-drop technique is then used to reconstruct the cartilage defect.
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he articular cartilage surfaces and acetabular labrum are essential to the normal function and physiology of the hip joint. Defects of either structure, or both as in this case, can result in significant reduction in function, destruction of joint space anatomy, progressive arthritis, and clinical symptomsdmost commonly hip pain.1 Hip pain may respond to conservative measures such as physiotherapy. However, when this treatment fails and consistent hip pain occurs beyond 3 months, arthroscopic surgical intervention should be considered.
From the Department of Emergency Medicine, Markham Stouffville Hospital (affiliated with University of Toronto) (L.E.M.), Markham, Ontario; and Department of Orthopaedic Surgery, Dalhousie University and Nova Scotia Health Authority (A.A.H., C.C., I.H.W.), Halifax, Nova Scotia, Canada. The authors report that they have no conflicts of interest in the authorship and publication of this article. Received August 22, 2016; accepted January 6, 2017. Address correspondence to Ivan H. Wong, M.D., M.A.C.M., F.R.C.S.C., Dip. Sports Medicine, Dalhousie University, 5955 Veterans’ Memorial Lane, Camp Hill Veterans’ Memorial Building, Room 2106, B3H2E1 Halifax, Nova Scotia, Canada. E-mail: [email protected] Crown Copyright Ó 2017 Published by Elsevier on behalf of the Arthroscopy Association of North America. All rights reserved. 2212-6287/16814/$36.00 http://dx.doi.org/10.1016/j.eats.2017.01.005
BST-CarGel (Piramal Healthcare, Laval, Quebec, Canada) is a mixture of chitosaneglycerol phosphate and blood used to improve tissue repair of hyaline cartilage in focal articular cartilage defects.2 BST-CarGel has been established as safe and effective for mid-duration cartilage repair in the knee. When compared with microfracture alone, treatment using BST-CarGel has resulted in sustained repair and considerably superior repair tissue quality and quantitydin addition to superior clinical benefit from baselinedat the 5-year mark.3 Implants comprising chitosaneglycerol phosphate and blood have resulted in augmented acute influx of subchondral osteoclasts through indirect mechanisms, producing substantially improved cartilage repair and cartilage-bone integrationdwithout induction of net bone resorption.4 Labral allograft reconstruction is a technique indicated for hip instability, pain, and a hypotrophic dysfunctional labrum. This technique is most commonly performed in young, active patients with minimal arthritis and an unrepairable or deficient labrum.5 Recent literature has pointed to the efficacy and safety of labral graft reconstruction, with one study’s results showing no major complications, revision surgical procedures, or conversion arthroplasties in gracilis autograft reconstruction patients (n ¼ 8; mean age, 34.6 years; age range, 18-58 years;
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Fig 1. Preoperative right weight-bearing hip. Black arrows indicate the joint space, and white arrows indicate the labrum. (A) Anteroposterior view showing joint space. (B) Dunn radiographic view. (C) Frog-leg radiographic view. (D) Sagittal magnetic resonance imaging (MRI) view showing delamination of labrum. (E) Axial MRI view. (F) Coronal MRI view.
2-year minimum outcomes).6 The purpose of this Technical Note is to demonstrate the use of both a labral allograft reconstruction and BST-CarGel reconstruction to repair an uncontained, full-thickness, focal cartilage defect of the acetabulum with a deficient labrum.
Fig 2. With the patient in the lateral decubitus position and right side up, the portal incision sites and anatomic structures are marked. Four portals were created: midanterior working portal for graft and BST-CarGel insertion (A), standard anterolateral viewing portal (B), posterolateral working portal (C), and accessory posterior portal for suction cannula (D).
Technique Preoperative Assessment Radiography shows small osteophyte formation with a normal joint space in the right hip (Fig 1 A-C). Magnetic resonance imaging shows early cartilaginous wear and osteophyte formation on the femoral head and acetabulum, with evidence of an acetabular cyst and labral tear (Fig 1 D-F).
Fig 3. Sterile field and procedure setup. The patient is in the lateral decubitus position and right side up on the traction table. The arrow indicates the patient’s head.
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Fig 4. Right hip viewed from anterolateral portal. (A) Missing labrum from the 12- to 3-o’clock position (white arrow), measuring 4 cm in length, and cartilaginous defect on acetabulum adjacent to missing labrum (black arrow), measuring 4 1.5 cm. (B) Acetabular osteoplasty on anterior rim with burr (arrow). (C) Curette (arrow) used to remove calcific layer on acetabular cartilage defect. (D) Femoral neck osteoplasty (arrow). (E) Microfracture (arrow) performed with 60 microfracture pick.
Positioning and Preparation The patient is positioned in the lateral decubitus position with the operative leg placed into a padded boot. The patient’s hip is then put into traction using the Hip Positioning System with Active Heel Technology (Smith & Nephew, Andover, MA). Portal incision sites are
marked (Fig 2), and the patient is draped, creating a sterile field (Fig 3). Arthroscopic Portals Four portals are created with C-arm imaging guidance. The anterolateral viewing portal (Fig 2) is created
Table 1. Pearls and Pitfalls of Operation7 Pearls Resect all tissue first, with labral debridement, cartilage delamination, and normal bony resection for femoroacetabular impingement (pincer and cam). Define labral loss and determine which area of the labrum is appropriate to keep and repair to reconstruction tissue. Define cartilage loss with curette to have adequate cartilage walls for adhering to BST-CarGel. Perform meticulous microfracture technique including removal of the calcific cartilage layer and adequate marrow bleeding. Use a separate suction spinal needle to keep the joint dry when inserting BST-CarGel to maintain good visualization. Re-create the 3-dimensional cartilage anatomy connecting native cartilage to the labral reconstruction using a drop-wise technique with BST-CarGel. Wait 15 min for the BST-CarGel construct to solidify before reducing the hip. Pitfalls The procedure is technically demanding and requires many steps. Excess fluid extravasation around the hip from increased surgical time or pump pressure will make it difficult to maintain a dry joint for final BST-CarGel insertion. The surgical team should try to perform steps simultaneously to decrease surgical time (i.e., graft preparation at start of case and BST-CarGel preparation when starting to dry joint). Poor timing of drying of the joint surfaces and mixture of BST-CarGel may lead to coagulation of patient blood in the mixture. Harvesting of a short allograft can occur (the surgeon should allow for an approximately 2-cm extension of allograft beyond the defect to allow for overlapping of graft margins).7
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Fig 5. Labral reconstruction. (A) Graft preparation on back table using 5-mm gracilis tendon graft, tubularized using baseball stitch (arrow). (B) Insertion of graft (arrows) using SMC knot viewed through anterolateral portal in right hip. (C) Final anchored labral reconstruction (arrow) viewed from anterolateral portal.
first for the purpose of diagnostic arthroscopy; it is specifically located anterior to the point of the greater trochanter. A midanterior working portal (Fig 2) is then created for graft and BST-CarGel insertion, spaced approximately at a sagittal line between the anterior superior iliac spine and across the superior greater trochanter with the spinal needle directed 45 cephalad and 30 toward the midline. An additional posterolateral working portal is made, and finally, an accessory posterior portal is placed percutaneously for a suction cannula for use during the insertion of BST-CarGel (Fig 2). With the establishment of all 4 portals, an inflow of saline solution through the anterolateral portal with the arthroscope is used to expand the joint space. Outflow is established through a cannula placed within the midanterior portal. An interportal capsulotomy is created with a radiofrequency ablator from the medial synovial fold to the lateral synovial fold to provide greater arthroscopic mobility and accessibility within the hip joint. Initial Evaluation Hemarthrosis is present in the right joint, and because of poor visualization, fluoroscopy is used to create a
midanterior portal for evacuation of this hemarthrosis. During evacuation of the hematoma, a site of complete cartilage loss (grade 4) becomes apparent on the acetabular rim. A labral tear is identified; however, the labrum is nonexistent from the 12- to 3-o’clock position to the psoas recess. Only the very edge of the lateral aspect of the labrum is able to provide a healthy margin for attachment of the labral allograft reconstruction. The labral defect is measured to be approximately 4 cm with a probe (Fig 4A). The psoas tendon is released at the level of the hip joint because it will rub on the medial aspect of the graft. Video 1 presents an overview of the surgical procedure performed, and Table 1 shows pearls and pitfalls. Osteochondral Lesion Assessment, Debridement, and Microfracture A high-speed burr is used to perform an acetabuloplasty to create a healthy, bleeding bone bed for labral reconstruction healing (Fig 4B). A small acetabular ring curette is used to remove the calcific cartilage from the acetabular defect to prepare the site for BST-CarGel
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Fig 6. BST-CarGel reconstruction. View from anterolateral portal in right hip. (A) Hip fluid drained using spinal needle (arrow) attached to suction through posterior accessory portal. (B) Neuro Patties (arrow) used to dry joint surfaces. (C) Drop-wise technique to reconstruct cartilage scaffold using bent spinal needle (arrow). (D) Final 3-dimensional contour of BST-CarGel reconstruction (arrow). (E) Reduction of femoral head (arrows) under vision after allowing 15 minutes for construct to solidify. (F) Redislocation of the femoral head showing 3-dimensional BST-CarGel reconstruction is intact (arrow).
Fig 7. Postoperative right weight-bearing hip. Black arrows indicate the joint space, and white arrows indicate the labrum. (A) Anteroposterior view with maintained joint space measurement. (B) Dunn radiographic view. (C) Frog-leg radiographic view. (D) Sagittal magnetic resonance imaging (MRI) view showing healed labrum. (E) Axial MRI view. (F) Coronal MRI view.
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Table 2. Advantages Versus Risks and Limitations of Operation11-13 Advantages The technique does not burn any bridges in patients with uncontained cartilage and labral defects. Minimally invasive arthroscopy does not require surgical hip dislocation with associated risks and morbidity.13 Reduced stiffness and improved function are achieved with BST-CarGel compared with microfracture alone.11 BST-CarGel results in superior cartilage tissue (quantity and improved structure) versus microfracture alone.11-13 High postoperative functional and pain reduction have been reported with labral reconstruction. Risks and limitations Insufficient marrow bleeding may lead to poor healing of cartilage reconstruction. Limited known long-term outcomes of labral reconstruction and BST-CarGel reconstruction are available. Level I evidence for cartilage reconstruction and function of BST-CarGel is only available for the knee. No Level I studies of labral reconstruction have been performed. No clinical outcome studies of both labral and cartilage reconstruction in patients have been performed. No long-term outcomes of labral reconstruction are available.
application (Fig 4C). The defect is estimated to be approximately 4 cm in length and 1.5 cm in width (Fig 4A). A 60 microfracture pick is then used after the calcific cartilage layer is removed with a curette in a standard fashion (Fig 4E). The saline solution inflow pump is turned off to ensure marrow bleeding into microfracture sites for promotion of cartilage reconstruction healing. Labral Allograft Preparation and Insertion On the back table, a gracilis tendon graft is flipped onto itself and stitched with a baseball stitch to make a 5-mm-diameter and 4-cm-long labral allograft (Fig 5A). Suture loops are tied to each end to facilitate the medial and lateral anchoring of the graft to the acetabulum. A single-loaded 2.3-mm Osteoraptor anchor (Smith & Nephew) is drilled medially over the psoas recess, and the graft is inserted into the joint by use of an SMC knot (Fig 5B). Next, a lateral 2.33-mm Osteoraptor anchor is placed through the posterolateral portal, and the graft is sutured to this using a Spectrum (Linvatec, Mississauga, Canada) needle driver through the tendon to hold it against the acetabular rim. Another SMC knot is used to fixate the lateral part of the graft to the acetabulum. Four more anchors are used to secure the allograft in the same fashion as a routine labral repair with circumferential sutures and tied with Revo knots (Fig 5C). BST-CarGel Preparation and Insertion After labral allograft reconstruction, a spinal needle is placed into the fovea through the accessory posterior portal directly attached to a suction for continuous drainage of fluid from the joint space as described
earlier (Fig 6A). Neuro Patties are used to dry the joint surfaces to allow BST-CarGel adherence to the cartilage defect (Fig 6B). While the joint space is being dried, 5 mL of blood is drawn by phlebotomy, with 4.5 mL of blood mixed with 0.3 mL of BST-CarGel. A surgical assistant holds the mixture in his or her hand and agitates it to prevent coagulation while thoroughly mixing the BST-CarGel matrix for thickened consistency. By use of a bent spinal needle through the midanterior portal, this BST-CarGel mixture is inserted by a dropwise technique (Fig 6C). Each drop is held at the tip of the needle to allow it to congeal, which in this case promotes adherence to the acetabular roof. This process is repeated until there is a complete 3-dimensional reconstruction of the cartilage defect (Fig 6D). Once the BST-CarGel is in place, we allow 10 minutes for the construct to solidify before hip reduction. At the end of this 10-minute period, the femoral head is reduced under direct vision, and the BST-CarGel remains in place with labral reconstruction helping to contain the defect (Fig 6E). The femoral head is then redislocated to confirm that the 3-dimensional shape of the BSTCarGel is intact (Fig 6F). The final product stays intact with successful completion of both the labral allograft and BST-CarGel reconstructions. Postoperative Care and Rehabilitation Patients are educated about the rehabilitation protocol and return to the clinic for follow-up at 2 weeks, when the staples are removed and radiographs obtained. Patients are instructed on weight bearing as follows: 25% weight bearing with crutches for 6 weeks and then 50% weight bearing at week 7, 75% weight bearing at week 8, and full weight bearing at week 9. Full range of motion is encouraged immediately. Postoperative magnetic resonance imaging at 1 year shows healing of the labrum and preservation of the joint space with good cartilage fill (Fig 7 D-F). Radiographs at 1 year show a normal contour and joint space of the right acetabulum, femoral head, and neck (Fig 7 A-C).
Discussion There have been separate treatments that have been described to address each of the aforementioned defects Table 3. Indications and Contraindications of Operation5,7 Indications Young, active individuals5 Irreparable or degenerative labrum5 Prior labral resection5 Minimum of 2 mm of joint space5 Focal cartilage defect Contraindications Global loss of cartilage in hip Suggested age >50 yr7 Kissing lesions on acetabulum and femur
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separately with good early results. Arthroscopic labral reconstruction has been described recently in cases of an irreparable or deficient labrum to help re-establish the function of the native labrum, with good early clinical outcomes.8-10 Cartilage reconstruction techniques have evolved recently. BST-CarGel has previously been used in the treatment of knee cartilage lesions with successful outcomes and has recently been applied and studied in hip chondral defects with promising results.3,11,12 As hip arthroscopy becomes more prevalent, more of these problems resulting from uncontained cartilage defects in young patients will be treated. There are few options for this group of patients. Final salvage techniques involve a total hip arthroplasty, using lowewear rate implants to maximize implant longevity. This is not a recommended option because the procedure cannot be reversed. Early clinical outcome studies of labral reconstructions have yielded good results, as have early clinical outcome studies of cartilage reconstruction procedures. However, no clinical outcome studies have examined when both of these problems occur together and are treated by both techniques. An advantage of performing allograft labral reconstruction with BST-CarGel cartilage reconstruction is that this technique does not burn any bridges. In our experience, this yields good early clinical results as a salvage procedure and has allowed young patients to have an improved quality of life with decreased pain and increased function. A limitation to this technique is the lack of clinical outcome studies for treatment of uncontained cartilage defects. Moreover, it is technically demanding with many steps, there is potential for excess swelling, the surgical time is increased, and there are increased costs for all the implants required. Additional risks and limitations of the operation are shown in Table 2. Furthermore, Table 3 presents some of the indications and contraindications of the treatment. In conclusion, this report illustrates the possibility of treating an uncontained cartilage defect of the acetabulum by combining currently accepted techniques that show promising early results. Although there are no clinical outcomes reported yet, this technique does not burn any bridges for future management and, if successful, can help to decrease pain, increase function, and perhaps delay the development of osteoarthritis.
Acknowledgment The authors express their gratitude to the research assistants Nicole Paquet and Jalisa den Hartog, Nova
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Scotia Health Authority, for their help in preparation of the manuscript. Laurel MacInnis would like to offer her deepest gratitude and appreciation for the mentorship of Dr. Ivan Wong, and the support of the Orthopaedic team and colleagues at the QEII Hospital in Halifax, Nova Scotia, along with the support of her family throughout the writing of this article.
References 1. Botser IB, Safran MR. Hip anatomy and biomechanics. In: Miller MD, Thompson SR, eds. Delee & Drez’s orthopaedic sports medicine. Amsterdam: Elsevier, 2015;917-932. 2. Hoemann CD, Hurtig M, Rossomacha E, et al. Chitosanglycerol phosphate/blood implants improve hyaline cartilage repair in ovine microfracture defects. J Bone Joint Surg Am 2005;87:2671-2686. 3. Shrive MS, Stanish WD, McCormack R, et al. BST-CarGel treatment maintains cartilage repair superiority over microfracture at 5 years in a multicenter randomized controlled trial. Cartilage 2015;6:62-72. 4. Chen G, Sun J, Lascau-Coman V, Chevrier A, Marchand C, Hoemann CD. Acute osteoclast activity following subchondral drilling is promoted by chitosan and associated with improved cartilage repair tissue integration. Cartilage 2011;2:173-185. 5. Ayeni OR, Alradwan H, de Sa D, Philippon MJ. The hip labrum reconstruction: Indications and outcomesdA systematic review. Knee Surg Sport Traumatol Arthrosc 2014;22:737-743. 6. Matsuda DK, Burchette RJ. Arthroscopic hip labral reconstruction with a gracilis autograft versus labral refixation: 2-year minimum outcomes. Am J Sports Med 2013;41:980-987. 7. Matsuda DK. Arthroscopic labral reconstruction with gracilis autograft. Arthrosc Tech 2012;1:e15-e21. 8. Byrd JW, Jones KS. Hip arthroscopy in athletes: 10-year follow-up. Am J Sports Med 2009;37:2140-2143. 9. White BJ, Herzog MM. Labral reconstruction: When to perform and how. Front Surg 2015;2:27. 10. Mook WR, Briggs KK, Philippon MJ. Evidence and approach for management of labral deficiency: The role for labral reconstruction. Sports Med Arthrosc 2015;23: 205-212. 11. Stanish WD, McCormack R, Forriol F, et al. Novel scaffold-based BST-CarGel treatment results in superior cartilage repair compared with microfracture in a randomized controlled trial. J Bone Joint Surg Am 2013;95: 1640-1650. 12. Tey M, Mas J, Pelfort X, Monllau JC. Arthroscopic treatment of hip chondral defects with bone marrow stimulation and BST-CarGel. Arthrosc Tech 2015;4:e29-e33. 13. Steinwachs MR, Waibl B, Mumme M. Arthroscopic treatment of cartilage lesion with microfracture and BSTCarGel. Arthrosc Tech 2014;3:e399-e402.
Abstract: Hip cartilage injuries are very common, with rates as high as 50% having been reported in some series; abnormal femoral acetabular contact can result in a full-thickness cartilage defect or labral lesion. The prevalence of labral lesions can be as high as 55%. This Technical Note describes an arthroscopic technique to reconstruct an uncontained, fullthickness, focal cartilage defect of the acetabulum, with reconstruction of the missing labrum using a gracilis allograft and use of a biological liquid scaffold for cartilage reconstruction. Capsulotomy, acetabuloplasty, and microfracture with marrow bleeding should be performed simultaneously with the gracilis allograft preparation. The graft is inserted and anchored to reconstruct the missing labrum and to re-create a contained defect. Suction and drying of the joint surfaces are performed while the mixture of BST-CarGel (Piramal Healthcare, Laval, Quebec, Canada) and blood is prepared. A drop-by-drop technique is then used to reconstruct the cartilage defect.
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he articular cartilage surfaces and acetabular labrum are essential to the normal function and physiology of the hip joint. Defects of either structure, or both as in this case, can result in significant reduction in function, destruction of joint space anatomy, progressive arthritis, and clinical symptomsdmost commonly hip pain.1 Hip pain may respond to conservative measures such as physiotherapy. However, when this treatment fails and consistent hip pain occurs beyond 3 months, arthroscopic surgical intervention should be considered.
From the Department of Emergency Medicine, Markham Stouffville Hospital (affiliated with University of Toronto) (L.E.M.), Markham, Ontario; and Department of Orthopaedic Surgery, Dalhousie University and Nova Scotia Health Authority (A.A.H., C.C., I.H.W.), Halifax, Nova Scotia, Canada. The authors report that they have no conflicts of interest in the authorship and publication of this article. Received August 22, 2016; accepted January 6, 2017. Address correspondence to Ivan H. Wong, M.D., M.A.C.M., F.R.C.S.C., Dip. Sports Medicine, Dalhousie University, 5955 Veterans’ Memorial Lane, Camp Hill Veterans’ Memorial Building, Room 2106, B3H2E1 Halifax, Nova Scotia, Canada. E-mail: [email protected] Crown Copyright Ó 2017 Published by Elsevier on behalf of the Arthroscopy Association of North America. All rights reserved. 2212-6287/16814/$36.00 http://dx.doi.org/10.1016/j.eats.2017.01.005
BST-CarGel (Piramal Healthcare, Laval, Quebec, Canada) is a mixture of chitosaneglycerol phosphate and blood used to improve tissue repair of hyaline cartilage in focal articular cartilage defects.2 BST-CarGel has been established as safe and effective for mid-duration cartilage repair in the knee. When compared with microfracture alone, treatment using BST-CarGel has resulted in sustained repair and considerably superior repair tissue quality and quantitydin addition to superior clinical benefit from baselinedat the 5-year mark.3 Implants comprising chitosaneglycerol phosphate and blood have resulted in augmented acute influx of subchondral osteoclasts through indirect mechanisms, producing substantially improved cartilage repair and cartilage-bone integrationdwithout induction of net bone resorption.4 Labral allograft reconstruction is a technique indicated for hip instability, pain, and a hypotrophic dysfunctional labrum. This technique is most commonly performed in young, active patients with minimal arthritis and an unrepairable or deficient labrum.5 Recent literature has pointed to the efficacy and safety of labral graft reconstruction, with one study’s results showing no major complications, revision surgical procedures, or conversion arthroplasties in gracilis autograft reconstruction patients (n ¼ 8; mean age, 34.6 years; age range, 18-58 years;
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Fig 1. Preoperative right weight-bearing hip. Black arrows indicate the joint space, and white arrows indicate the labrum. (A) Anteroposterior view showing joint space. (B) Dunn radiographic view. (C) Frog-leg radiographic view. (D) Sagittal magnetic resonance imaging (MRI) view showing delamination of labrum. (E) Axial MRI view. (F) Coronal MRI view.
2-year minimum outcomes).6 The purpose of this Technical Note is to demonstrate the use of both a labral allograft reconstruction and BST-CarGel reconstruction to repair an uncontained, full-thickness, focal cartilage defect of the acetabulum with a deficient labrum.
Fig 2. With the patient in the lateral decubitus position and right side up, the portal incision sites and anatomic structures are marked. Four portals were created: midanterior working portal for graft and BST-CarGel insertion (A), standard anterolateral viewing portal (B), posterolateral working portal (C), and accessory posterior portal for suction cannula (D).
Technique Preoperative Assessment Radiography shows small osteophyte formation with a normal joint space in the right hip (Fig 1 A-C). Magnetic resonance imaging shows early cartilaginous wear and osteophyte formation on the femoral head and acetabulum, with evidence of an acetabular cyst and labral tear (Fig 1 D-F).
Fig 3. Sterile field and procedure setup. The patient is in the lateral decubitus position and right side up on the traction table. The arrow indicates the patient’s head.
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Fig 4. Right hip viewed from anterolateral portal. (A) Missing labrum from the 12- to 3-o’clock position (white arrow), measuring 4 cm in length, and cartilaginous defect on acetabulum adjacent to missing labrum (black arrow), measuring 4 1.5 cm. (B) Acetabular osteoplasty on anterior rim with burr (arrow). (C) Curette (arrow) used to remove calcific layer on acetabular cartilage defect. (D) Femoral neck osteoplasty (arrow). (E) Microfracture (arrow) performed with 60 microfracture pick.
Positioning and Preparation The patient is positioned in the lateral decubitus position with the operative leg placed into a padded boot. The patient’s hip is then put into traction using the Hip Positioning System with Active Heel Technology (Smith & Nephew, Andover, MA). Portal incision sites are
marked (Fig 2), and the patient is draped, creating a sterile field (Fig 3). Arthroscopic Portals Four portals are created with C-arm imaging guidance. The anterolateral viewing portal (Fig 2) is created
Table 1. Pearls and Pitfalls of Operation7 Pearls Resect all tissue first, with labral debridement, cartilage delamination, and normal bony resection for femoroacetabular impingement (pincer and cam). Define labral loss and determine which area of the labrum is appropriate to keep and repair to reconstruction tissue. Define cartilage loss with curette to have adequate cartilage walls for adhering to BST-CarGel. Perform meticulous microfracture technique including removal of the calcific cartilage layer and adequate marrow bleeding. Use a separate suction spinal needle to keep the joint dry when inserting BST-CarGel to maintain good visualization. Re-create the 3-dimensional cartilage anatomy connecting native cartilage to the labral reconstruction using a drop-wise technique with BST-CarGel. Wait 15 min for the BST-CarGel construct to solidify before reducing the hip. Pitfalls The procedure is technically demanding and requires many steps. Excess fluid extravasation around the hip from increased surgical time or pump pressure will make it difficult to maintain a dry joint for final BST-CarGel insertion. The surgical team should try to perform steps simultaneously to decrease surgical time (i.e., graft preparation at start of case and BST-CarGel preparation when starting to dry joint). Poor timing of drying of the joint surfaces and mixture of BST-CarGel may lead to coagulation of patient blood in the mixture. Harvesting of a short allograft can occur (the surgeon should allow for an approximately 2-cm extension of allograft beyond the defect to allow for overlapping of graft margins).7
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Fig 5. Labral reconstruction. (A) Graft preparation on back table using 5-mm gracilis tendon graft, tubularized using baseball stitch (arrow). (B) Insertion of graft (arrows) using SMC knot viewed through anterolateral portal in right hip. (C) Final anchored labral reconstruction (arrow) viewed from anterolateral portal.
first for the purpose of diagnostic arthroscopy; it is specifically located anterior to the point of the greater trochanter. A midanterior working portal (Fig 2) is then created for graft and BST-CarGel insertion, spaced approximately at a sagittal line between the anterior superior iliac spine and across the superior greater trochanter with the spinal needle directed 45 cephalad and 30 toward the midline. An additional posterolateral working portal is made, and finally, an accessory posterior portal is placed percutaneously for a suction cannula for use during the insertion of BST-CarGel (Fig 2). With the establishment of all 4 portals, an inflow of saline solution through the anterolateral portal with the arthroscope is used to expand the joint space. Outflow is established through a cannula placed within the midanterior portal. An interportal capsulotomy is created with a radiofrequency ablator from the medial synovial fold to the lateral synovial fold to provide greater arthroscopic mobility and accessibility within the hip joint. Initial Evaluation Hemarthrosis is present in the right joint, and because of poor visualization, fluoroscopy is used to create a
midanterior portal for evacuation of this hemarthrosis. During evacuation of the hematoma, a site of complete cartilage loss (grade 4) becomes apparent on the acetabular rim. A labral tear is identified; however, the labrum is nonexistent from the 12- to 3-o’clock position to the psoas recess. Only the very edge of the lateral aspect of the labrum is able to provide a healthy margin for attachment of the labral allograft reconstruction. The labral defect is measured to be approximately 4 cm with a probe (Fig 4A). The psoas tendon is released at the level of the hip joint because it will rub on the medial aspect of the graft. Video 1 presents an overview of the surgical procedure performed, and Table 1 shows pearls and pitfalls. Osteochondral Lesion Assessment, Debridement, and Microfracture A high-speed burr is used to perform an acetabuloplasty to create a healthy, bleeding bone bed for labral reconstruction healing (Fig 4B). A small acetabular ring curette is used to remove the calcific cartilage from the acetabular defect to prepare the site for BST-CarGel
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Fig 6. BST-CarGel reconstruction. View from anterolateral portal in right hip. (A) Hip fluid drained using spinal needle (arrow) attached to suction through posterior accessory portal. (B) Neuro Patties (arrow) used to dry joint surfaces. (C) Drop-wise technique to reconstruct cartilage scaffold using bent spinal needle (arrow). (D) Final 3-dimensional contour of BST-CarGel reconstruction (arrow). (E) Reduction of femoral head (arrows) under vision after allowing 15 minutes for construct to solidify. (F) Redislocation of the femoral head showing 3-dimensional BST-CarGel reconstruction is intact (arrow).
Fig 7. Postoperative right weight-bearing hip. Black arrows indicate the joint space, and white arrows indicate the labrum. (A) Anteroposterior view with maintained joint space measurement. (B) Dunn radiographic view. (C) Frog-leg radiographic view. (D) Sagittal magnetic resonance imaging (MRI) view showing healed labrum. (E) Axial MRI view. (F) Coronal MRI view.
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Table 2. Advantages Versus Risks and Limitations of Operation11-13 Advantages The technique does not burn any bridges in patients with uncontained cartilage and labral defects. Minimally invasive arthroscopy does not require surgical hip dislocation with associated risks and morbidity.13 Reduced stiffness and improved function are achieved with BST-CarGel compared with microfracture alone.11 BST-CarGel results in superior cartilage tissue (quantity and improved structure) versus microfracture alone.11-13 High postoperative functional and pain reduction have been reported with labral reconstruction. Risks and limitations Insufficient marrow bleeding may lead to poor healing of cartilage reconstruction. Limited known long-term outcomes of labral reconstruction and BST-CarGel reconstruction are available. Level I evidence for cartilage reconstruction and function of BST-CarGel is only available for the knee. No Level I studies of labral reconstruction have been performed. No clinical outcome studies of both labral and cartilage reconstruction in patients have been performed. No long-term outcomes of labral reconstruction are available.
application (Fig 4C). The defect is estimated to be approximately 4 cm in length and 1.5 cm in width (Fig 4A). A 60 microfracture pick is then used after the calcific cartilage layer is removed with a curette in a standard fashion (Fig 4E). The saline solution inflow pump is turned off to ensure marrow bleeding into microfracture sites for promotion of cartilage reconstruction healing. Labral Allograft Preparation and Insertion On the back table, a gracilis tendon graft is flipped onto itself and stitched with a baseball stitch to make a 5-mm-diameter and 4-cm-long labral allograft (Fig 5A). Suture loops are tied to each end to facilitate the medial and lateral anchoring of the graft to the acetabulum. A single-loaded 2.3-mm Osteoraptor anchor (Smith & Nephew) is drilled medially over the psoas recess, and the graft is inserted into the joint by use of an SMC knot (Fig 5B). Next, a lateral 2.33-mm Osteoraptor anchor is placed through the posterolateral portal, and the graft is sutured to this using a Spectrum (Linvatec, Mississauga, Canada) needle driver through the tendon to hold it against the acetabular rim. Another SMC knot is used to fixate the lateral part of the graft to the acetabulum. Four more anchors are used to secure the allograft in the same fashion as a routine labral repair with circumferential sutures and tied with Revo knots (Fig 5C). BST-CarGel Preparation and Insertion After labral allograft reconstruction, a spinal needle is placed into the fovea through the accessory posterior portal directly attached to a suction for continuous drainage of fluid from the joint space as described
earlier (Fig 6A). Neuro Patties are used to dry the joint surfaces to allow BST-CarGel adherence to the cartilage defect (Fig 6B). While the joint space is being dried, 5 mL of blood is drawn by phlebotomy, with 4.5 mL of blood mixed with 0.3 mL of BST-CarGel. A surgical assistant holds the mixture in his or her hand and agitates it to prevent coagulation while thoroughly mixing the BST-CarGel matrix for thickened consistency. By use of a bent spinal needle through the midanterior portal, this BST-CarGel mixture is inserted by a dropwise technique (Fig 6C). Each drop is held at the tip of the needle to allow it to congeal, which in this case promotes adherence to the acetabular roof. This process is repeated until there is a complete 3-dimensional reconstruction of the cartilage defect (Fig 6D). Once the BST-CarGel is in place, we allow 10 minutes for the construct to solidify before hip reduction. At the end of this 10-minute period, the femoral head is reduced under direct vision, and the BST-CarGel remains in place with labral reconstruction helping to contain the defect (Fig 6E). The femoral head is then redislocated to confirm that the 3-dimensional shape of the BSTCarGel is intact (Fig 6F). The final product stays intact with successful completion of both the labral allograft and BST-CarGel reconstructions. Postoperative Care and Rehabilitation Patients are educated about the rehabilitation protocol and return to the clinic for follow-up at 2 weeks, when the staples are removed and radiographs obtained. Patients are instructed on weight bearing as follows: 25% weight bearing with crutches for 6 weeks and then 50% weight bearing at week 7, 75% weight bearing at week 8, and full weight bearing at week 9. Full range of motion is encouraged immediately. Postoperative magnetic resonance imaging at 1 year shows healing of the labrum and preservation of the joint space with good cartilage fill (Fig 7 D-F). Radiographs at 1 year show a normal contour and joint space of the right acetabulum, femoral head, and neck (Fig 7 A-C).
Discussion There have been separate treatments that have been described to address each of the aforementioned defects Table 3. Indications and Contraindications of Operation5,7 Indications Young, active individuals5 Irreparable or degenerative labrum5 Prior labral resection5 Minimum of 2 mm of joint space5 Focal cartilage defect Contraindications Global loss of cartilage in hip Suggested age >50 yr7 Kissing lesions on acetabulum and femur
UNCONTAINED ACETABULAR CARTILAGE DEFECT
separately with good early results. Arthroscopic labral reconstruction has been described recently in cases of an irreparable or deficient labrum to help re-establish the function of the native labrum, with good early clinical outcomes.8-10 Cartilage reconstruction techniques have evolved recently. BST-CarGel has previously been used in the treatment of knee cartilage lesions with successful outcomes and has recently been applied and studied in hip chondral defects with promising results.3,11,12 As hip arthroscopy becomes more prevalent, more of these problems resulting from uncontained cartilage defects in young patients will be treated. There are few options for this group of patients. Final salvage techniques involve a total hip arthroplasty, using lowewear rate implants to maximize implant longevity. This is not a recommended option because the procedure cannot be reversed. Early clinical outcome studies of labral reconstructions have yielded good results, as have early clinical outcome studies of cartilage reconstruction procedures. However, no clinical outcome studies have examined when both of these problems occur together and are treated by both techniques. An advantage of performing allograft labral reconstruction with BST-CarGel cartilage reconstruction is that this technique does not burn any bridges. In our experience, this yields good early clinical results as a salvage procedure and has allowed young patients to have an improved quality of life with decreased pain and increased function. A limitation to this technique is the lack of clinical outcome studies for treatment of uncontained cartilage defects. Moreover, it is technically demanding with many steps, there is potential for excess swelling, the surgical time is increased, and there are increased costs for all the implants required. Additional risks and limitations of the operation are shown in Table 2. Furthermore, Table 3 presents some of the indications and contraindications of the treatment. In conclusion, this report illustrates the possibility of treating an uncontained cartilage defect of the acetabulum by combining currently accepted techniques that show promising early results. Although there are no clinical outcomes reported yet, this technique does not burn any bridges for future management and, if successful, can help to decrease pain, increase function, and perhaps delay the development of osteoarthritis.
Acknowledgment The authors express their gratitude to the research assistants Nicole Paquet and Jalisa den Hartog, Nova
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Scotia Health Authority, for their help in preparation of the manuscript. Laurel MacInnis would like to offer her deepest gratitude and appreciation for the mentorship of Dr. Ivan Wong, and the support of the Orthopaedic team and colleagues at the QEII Hospital in Halifax, Nova Scotia, along with the support of her family throughout the writing of this article.
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