Abductor pollicis longus tendon arthroplasty of the trapezio-metacarpal joint: Surgical technique and results Tendon interposition
resection arthroplasty
teoarthrosis of the first carpometacarpal operation is described
of the trapezium
is a valuable tool in treating os-
joint. A previously unreported modification of such an
in which a part of the abductor
pollicis longus tendon is used as an
interposition material. This technique was employed in a series of thirty-nine thumbs. After a minimal follow-up period of 2 years, the results of the operation are graded excellent in 48% of the patients, good in 35%, and average in the rest. Grip strength, as well as pinch strength, is about three quarters of the normal average. No patient needed a further operation. (J SURC
Dror Robinson, Nahum
Halperin,
MD,
Maurice
MD, Zerifin,
Aghasi,
T
From the Department of Orthopedic Surgery “A”, Assaf Harofeh Medical Center, Zerifm, Israel; and Sackler Medical School, Tel-Aviv University, Tel Aviv, Israel. Received for publication March 29, 1990.
June 13, 1989; accepted
in revised form
No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. Reprint requests: Dror Robinson, MD, Department of Orthopaedic Surgery “A,” Assaf Harofeh Medical Center, Z&fin 70300 Israel. 311122928
THE JOURNAL OF HAND SURGERY
MD,
and
Israel
he thumb carpometacarpal joint is frequently affected by osteoarthrosis. Simple excision of the trapezium results in an unstable and painful joint.’ In addition in up to one third of patients an adduction deformity of the thumb develops. Implantation of a Swanson’s silicone rubber trapezium implant2 carries a high morbidity rate. In up to one third of patients the implant dislocates. Furthermore, such implants can cause silicone-particle induced synovitis resulting in a painful and dysfunctional thumb and wrist.3-5 The use of resection arthroplasty of the trapezium combined with tendon interposition was first described by Gervis.6 Since then several reports describing this procedure and its results have appeared. ‘. 3.’ Most authors used a part of the flexor carpi radialis (FCR) rolled up like an anchovy as an interposition material.*-” Some
504
HAND
1991;16A:504-9.)
have done a similar procedure using the tendon of the palmaris longus as an interposition graft.’ In the last 10 years we have used part of the abductor pollicis longus (APL) as the interposition material. Approach
and technique
A dorsoradial skin incision is made (Fig. 1). The incision is started 1 cm distal to the base of the first metacarpal bone and continues proximally over the carpometacarpal joint and through the anatomical snuffbox, ending about 2Y2 cm proximal to the radial styloid. The branches of the superficial radial nerve are identified and gently retracted. The dorsal carpal ligament is exposed and incised, and the first dorsal tendon compartment is opened. The tendons of the extensor pollicis brevis (EPB) and the APL are retracted radialward (Fig. 1). The radial artery is identified as it courses along the snuff-box, and is carefully dissected and retracted ulnarward. At this stage a good exposure of the capsule of the carpometacarpal joint is achieved. The capsule is longitudinally incised and the trapezium is exposed. It is later excised piecemeal. Care should be taken not to traumatize the tendon of the FCR on the palmar aspect of the trapezium. It is also very important to excise osteophytes that might be present between the first and second metacarpal bones. The APL usually consist of more than one tendon at this level. One of the tendons is proximally dissected
Vol. 16A, No. 3 May 1991
Abductor pollicis longus tendon arthroplasty
Fig. 1. Exposure of the tendon of the APL (arrowhead) as well as the joint capsule, after retraction of radial artery and thumb extensors.
Fig. 2. Dissection and proximal release of one of the slips of the APL (thick arrowhead). Note the cavity created after the excision of the trapezium (small arrowhead). Scaphoid (thin arrow).
505
506
The Journal of HAND SURGERY
Robinson, Aghasi, and Halperin
Fig. 3. The released slip of the APL is rolled up into the cavity (arrow) and the joint capsule is sutured over it.
Table I. Grading of the results after operation:
After minimal follow-up of 2 years Grade
Pain
Range of motion
Excellent
None
Fllll
Good
None
Fair
Thumb stress
Poor
Pain at rest
75% < ROM of normal 50%-75% of normal < 50% of normal
Grip power Nearly fill1 Nearly full Mildly reduced Severely
and released about 3.5 cm proximal to the trapezium (Fig. 2). It is rolled up and used as a spacer by suturing it to the FCR tendon (Fig. 3). The capsule edges are approximated and sutured with 2-O absorbable sutures, and the skin incision closed, leaving a Penrose drain behind. In this stage any previous adduction contracture is corrected by appropriate soft tissue release. Postoperative
care
The hand is placed in a plaster of paris thumb spica cast for 3 weeks. The drain is removed 24 hours after the operation, and skin sutures are removed 6 to 7 days
later. The operation is usually done on an ambulatory basis, unless serious concurrent disorders exist. Clinical material
Between January 1, 1982 and December 3 1, 1987, 39 thumbs in 23 patients had operations. Ages averaged 54 years (range, 46 to 80), and 19 of 23 patients were women. The indication for surgery was severe pain located at the base of the thumb limiting the patient in activities of daily life. All patients were treated before being considered for surgery by antiinflammatory medication, as well as rest periods for a minimal duration of 6 months. Patients were not considered for surgery unless they had radiographic evidence of at least stage II osteoarthrosis of the trapeziometacqal joint.7 Eight of 39 joints had a stage II disease; 22 of 39 were stage III, and the rest were stage IV. However, the indication for operation was always clinical and not based solely on radiographs. Grip power was measured with an adjustable hand dynamometer (JAMAR Model 1, J. A. Preston Corp., Clifton, N .J.) , according to the protocol suggested by Mathiowetz et al.“’ I* Grip power was measured in the second handle position for all subjects. The average results of three consecutive measurements were recorded, provided they were within 10% of each
Vol. 16A, No. 3 May 1991
Abductor pollicis longus tendon arthroplasty
507
Table II. Grip power in patients undergoing tendon arthroplasty after a minimum follow-up of 2 years (rounded to closest pound; compared with results published by Mathiowetz et al.“) No.
Age
Sex
Hand
Mean
SD
8 of normal
5 2 7 4 6 4 4 4 1 1
45-49 45-49 50-59 50-59 60-69 60-69 60-69 60-69 70-79 70-79
F
R
F
L
F F F F M M
R L R L R L R L
56 50 49 44 42 33 73 62 35 29
12.4 14.2 9.5 8.2 10.7 10.0 13.4 12.5 9.8 8.1
90.3% 89.2% 80.1% 84.0% 80.6% 76.7% 80.7% 80.7% 68.3% 74.3%
F F
Table III. Pinch power in patients undergoing tendon atthroplasty after a minimum follow-up of 2 years (rounded to closest pound; compared with results published by Mathiowetz et al.“) Tip pinch
Key pinch
No.
&e
Sex
Hand
Mean
SD
8
Mean
SD
%
5 2 7 4 6 4 4 4 1 1
45-49 45-49 50-59 50-59 60-69 60-69 60-69 60-69 70-79 70-79
F F F F F F M M F F
R L R L R L R L R L
9 8 9 8 7 7 12 11 6 6
2.4 4.2 1.5 3.3 2.1 1.4 2.4 2.5 1.4 0.9
68% 66% 75% 73% 70% 68% 73% 72% 62% 64%
13 12 11 10 12 11 17 15 10 10
2.1 2.3 2.5 1.9 2.9 3.1 1.6 2.5 2.3 2.5
74% 72% 68% 62% 79% 75% 73% 68% 76% 80%
other. Otherwise, the test was repeated after 10 minutes. As grip power is influenced by the position of the upper limb, all patients were examined in a standardized position,“~ ‘* that is, while sitting down with the shoulder adducted, the elbow flexed to 90 degrees, the forearm and wrist in neutral position. The results were compared with those previously reported in the literature.“. I2 Pinch strength was measured with a pinch gauge (B&L Pinch Gauge, B&L Engineering, Sante Fe Springs, Calif.). Tip pinch strength, as well as key pinch and palmar pinch was measured and results were compared with previously published results. ‘I. ‘*Results were graded by one of the authors (M. A.) as shown in Table I. Results All patients in this series were followed-up by one of the authors (M. A.), and average follow-up periods
available were 53 months. A minimal follow-up period of 2 years was available for all patients. All patients reported an increase of pain in the first postoperative week. Later their condition improved rapidly, and none of them complained of pain at rest later than 1 week after surgery. One month after the operation the patients could perform light work with the hand. Grip strength was assessed both by recording of patients’ complaints and answers to directed enquiries. In addition, measurements of power-grip, as well as lateral pinch and end-to-end pinch were made during the follow-up period. Subjective grip power improved slowly after operation, with a plateau being reached after 1 year. More than 90% of patients (36 of 39) were satisfied with thumb power 1 year and later after the operation. None had to modify their daily activities because of lack of power. The results of dynamometer measurements are presented in Tables II and III. Grip power at 2 years or later after the operation averaged
508
Robinson, Aghasi, and Halperin
about 80% of the average normal result in patients of similar age. Pinch strength was somewhat weaker and averaged 65% to 70% of normal. Mobility of the joint was measured in a similar manner to that described by Weilby.3 However, since many of the patients had bilateral disease, mobility was expressed as a percentage of expected normal range of motion of the first carpometacarpal joint. The mobility is expressed as a percentage of the mobility in the unoperated hand. This method is also a problematic one since the range of motion of this joint is variable. Active mobility achieved 1 year after operation was 85% of the expected normal range (range, 73% to 100%). However, both methods yielded similar results (motion of the operated thumb as a percentage of that of the unoperated thumb averaged 92%). The major motion diminished by the operation is extension. Thumb range of abduction was not affected by the removal of one of the tendon slips of the abductor pollicis longus. Radiographically, the average scapho-first metacarpal gap was 7 mm (range, 5 to 8 m), the metacarpal was not subluxated in any of the cases. There was no correlation between gap size and final result; however, this could be due to the small number of cases with unsatisfactory results. Results were graded as excellent in 48% of patients (11 of 23), good in 35% (8 of 23), and fair in 17% (4 of 23). Hands graded as fair were so graded largely because of a mild loss of thumb power. There were few complications. No cases of infection, instability, or thumb stiffness were seen. One patient had a transient lesion of the superficial radial nerve. The nerve lesion eventually resolved completely. In two patients a fragment of the osteophyte, which commonly occurs between the first and second metacarpals, was left behind. These two patients were the only ones who later suffered from some pain during stressful thumb movements. Neither of them had any pain at rest, probably because of the small size of the fragment. The thumb range of motion was unaffected in these patients; however, they both had some loss of grip power. Discussion The principal aim of the operation is to achieve a stable and painless thumb. Additional aims are achieving reasonable mobility and strength. The advantage of interposition tendon arthroplasty is the simplicity of the operation. The various implant arthroplasties have several drawbacks. The implant life span is limited and while early results are encouraging, later deterioration is to be expected at least in some cases.‘, 5 Furthermore, cemented implants are difficult to revise after failure.‘, I3 Another potential complication of silicone
The Journal of HAND SURGERY
implants is development of silicone-induced synovitis.5 In contrast, ligament interposition arthroplasty is a surgical procedure of smaller magnitude at least according to some of the opinions expressed in the literature” as well as according to our own experience. Furthermore, as a biological material is used as a spacer, its good short-term results are expected to be long lasting. Several methods of tendon interposition arthroplasty have been described. Either the palmaris longus’ or the flexor carpi radialis tendons’. ‘O have been used as spacers. The main advantage inherent in the use of the palmaris longus tendon is its being relatively functionally unimportant to the human hand. However, it is only present in about 85% of limbs. I4 In some of the cases the tendon, although present, is not useful because of a bulky muscle belly leaving only a short length of available tendon. In some other cases the tendon is very slim. In both of these instances, accounting for 42% of cases in one series,’ not enough material is available for interposition. The use of an absorbable gelatin sponge (Gelfoam) or some other synthetic material thus becomes necessary.’ Use of the flexor carpi radialis has yielded predictably good results.‘, lo A potential disadvantage is the relatively small amount of spacer material available. This leads to a relatively small gap averaging 1.6 mm.” This might prove significant since the result of the operation has been linked to the size of the gap as seen on radiographs.” A further potential disadvantage of both of these techniques is the necessity of additional soft tissue dissection to retrieve the tendons. Weilby’ has described the imbrication of the abductor pollicis longus tendon as a salvage operation after failure of trapezia1 implants. In this procedure the tendon is sutured to the periosteum and soft tissue left in the space formerly occupied by the implant. Since this procedure achieved satisfactory results, the same author later used a modification as a primary procedure.3s I5 This procedure involved splitting a strip of the flexor carpi radialis and imbricating it around the abductor pollicis longus tendon. In up to 9% of patients de Quervain’s tenosynovitis or rupture of the abductor pollicis longus tendon caused by inflammation results. This complication could be prevented by performing a preventive first extensor compartment release.3 The procedure described by us has the advantage of preserving the flexor carpi radialis tendon. The abductor pollicis longus tendon, although classically depicted as a single thick tendon, is actually composed of two to three or more slips in most cases.“. I6 This allows the surgeon to dissect only one of the slips and use it as an interposition spacer. Leaving the rest of the tendonslips intact preserves the function of the abductor pol-
Vol. 16A, No. 3 May 1991
licis Iongus. A prophylactic first extensor compartment release is performed by us in all patients. This procedure obviates the complication of de Quervain’s tendinitis or even tendon rupture. Several important pitfalls exist in this operation. First, great care should be exercised during the initial skin incision and subcutaneous dissection not to harm the branches of the superficial radial nerve. All branches encountered should be carefully protected, since a neuroma could lead to an unsatisfactory result. Second, the radial artery should be protected and we also strongly recommend performing Allen’s test before operation to ascertain the availability of a collateral circulation. Third, the medial osteophyte present between the metacarpals should be removed because even a small fragment left behind leads to a painful and weak grip. The last important point is that the interposed tendon must be well anchored in its place. Dislocation of the tendon would lead to a smaller gap and worse clinical results. We consider this procedure successful since most patients achieve either excellent or good results. The most feared complication in this procedure is probably damage to the superficial radial nerve, with ensuing development of neuromas . This complication has been avoided in our series, as well as other series,3* ‘O by careful dissection and protection of the various branches. Though pain is usually relieved by the time of cast removal 3 weeks after the operation, improvement of grip power is slow, taking as much as 1 year. It is essential to inform the patient before the operation of the long term of gradual improvement of function. This would avoid patient disillusionment, with possible lit-
igation . REFERENCES 1. Weilby A. Surgical treatment of osteoarthritis of the
cargo-metacarpal joint of the thumb. Stand J Plast Reconstr Surg 1971;5:136-41. 2. Swanson AB, Swanson GG. Reconstruction of the thumb basal joints; development and current status of implant techniques. Clin Orthop 1987;220:68-85.
Abductor pollicis longus tendon arthroplasty
509
3. Weilby A. A tendon interposition arthroplasty of the first carpo-metacarpal joint. J HAND SURG 3988;13B:423-5. 4. Hofammann DY, Ferlic DC, Clayton ML. Arthroplasty of the basal joint of the thumb using a silicone prosthesis: long term follow-up. J Bone Joint Surg 1987;69A: 993-7. 5. Pellegrini VD, Burton RI. Surgical management of basal joint arthritis of the thumb, Part I: long term results of silicone implant arthroplasty. J HAND SURG 1986&30924. 6. Gervis WI-I. Excision of the trapezium for osteoarthritis of the trapezio-metacarpal joint. J Bone Joint Surg 1949;31:537-9. 7. Dell PC, Muniz RB. Interposition arthroplasty of the trapezio-metacarpal joint for osteoarthritis. Clin Orthop 1987;220:27-34. 8. Burton RI, Pellegrini VD. Surgical management of basal joint arthritis of the thumb: Part II: ligament reconstruction with tendon interposition arthroplasty. J HAND SURG 1986;11A:324-32. 9. Eaton RG, Glickel SZ, Littler JW. Tendon interposition arthroplasty for degenerative arthritis of the trapeziometacarpal joint of the thumb. J HAND SURG 1985;lOA: 645-54. of the trapezio10. Froimson AI. Tendon arthroplasty metacarpal joint. Clin Orthop 1970;70: 191-9. 11. Mathiowetz V, Kashman N, Volland G, Weber K, Dowe M, Rogers S. Grip and pinch strength: normative data for adults. Arch Phys Med Rehabil 1985;66:69-74. 12. Mathiowetz V, Weber K, Volland G, Kashman N. Reliability and validity of hand strength evaluation. J HAND SURG 1984;9A:222-6. 13. Weilby A, Sondorf J. Results following removal of silicone trapezium implants. J HAND SURG 1978;3: 154-6. 14. Schneider LH, Hunter JM. Flexor tendons - Late reconstruction. In: Green DP, editor: Operative Hand Surgery, ed. 2. New York, 1988, Churchill Livingstone, pp 19692044. 15. Froimson A. Tenosynovitis and Tennis Elbow. In: Green DP, editor: Operative Hand Surgery, ed. 2. New York, 1988, Churchill Livingstone, pp 2117-2134. 16. Strandell G. Variations of the anatomy in stenosing tenosynovitis at the radial styloid process. Acta Chir Stand 1957;113:234-240.
resection arthroplasty
teoarthrosis of the first carpometacarpal operation is described
of the trapezium
is a valuable tool in treating os-
joint. A previously unreported modification of such an
in which a part of the abductor
pollicis longus tendon is used as an
interposition material. This technique was employed in a series of thirty-nine thumbs. After a minimal follow-up period of 2 years, the results of the operation are graded excellent in 48% of the patients, good in 35%, and average in the rest. Grip strength, as well as pinch strength, is about three quarters of the normal average. No patient needed a further operation. (J SURC
Dror Robinson, Nahum
Halperin,
MD,
Maurice
MD, Zerifin,
Aghasi,
T
From the Department of Orthopedic Surgery “A”, Assaf Harofeh Medical Center, Zerifm, Israel; and Sackler Medical School, Tel-Aviv University, Tel Aviv, Israel. Received for publication March 29, 1990.
June 13, 1989; accepted
in revised form
No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. Reprint requests: Dror Robinson, MD, Department of Orthopaedic Surgery “A,” Assaf Harofeh Medical Center, Z&fin 70300 Israel. 311122928
THE JOURNAL OF HAND SURGERY
MD,
and
Israel
he thumb carpometacarpal joint is frequently affected by osteoarthrosis. Simple excision of the trapezium results in an unstable and painful joint.’ In addition in up to one third of patients an adduction deformity of the thumb develops. Implantation of a Swanson’s silicone rubber trapezium implant2 carries a high morbidity rate. In up to one third of patients the implant dislocates. Furthermore, such implants can cause silicone-particle induced synovitis resulting in a painful and dysfunctional thumb and wrist.3-5 The use of resection arthroplasty of the trapezium combined with tendon interposition was first described by Gervis.6 Since then several reports describing this procedure and its results have appeared. ‘. 3.’ Most authors used a part of the flexor carpi radialis (FCR) rolled up like an anchovy as an interposition material.*-” Some
504
HAND
1991;16A:504-9.)
have done a similar procedure using the tendon of the palmaris longus as an interposition graft.’ In the last 10 years we have used part of the abductor pollicis longus (APL) as the interposition material. Approach
and technique
A dorsoradial skin incision is made (Fig. 1). The incision is started 1 cm distal to the base of the first metacarpal bone and continues proximally over the carpometacarpal joint and through the anatomical snuffbox, ending about 2Y2 cm proximal to the radial styloid. The branches of the superficial radial nerve are identified and gently retracted. The dorsal carpal ligament is exposed and incised, and the first dorsal tendon compartment is opened. The tendons of the extensor pollicis brevis (EPB) and the APL are retracted radialward (Fig. 1). The radial artery is identified as it courses along the snuff-box, and is carefully dissected and retracted ulnarward. At this stage a good exposure of the capsule of the carpometacarpal joint is achieved. The capsule is longitudinally incised and the trapezium is exposed. It is later excised piecemeal. Care should be taken not to traumatize the tendon of the FCR on the palmar aspect of the trapezium. It is also very important to excise osteophytes that might be present between the first and second metacarpal bones. The APL usually consist of more than one tendon at this level. One of the tendons is proximally dissected
Vol. 16A, No. 3 May 1991
Abductor pollicis longus tendon arthroplasty
Fig. 1. Exposure of the tendon of the APL (arrowhead) as well as the joint capsule, after retraction of radial artery and thumb extensors.
Fig. 2. Dissection and proximal release of one of the slips of the APL (thick arrowhead). Note the cavity created after the excision of the trapezium (small arrowhead). Scaphoid (thin arrow).
505
506
The Journal of HAND SURGERY
Robinson, Aghasi, and Halperin
Fig. 3. The released slip of the APL is rolled up into the cavity (arrow) and the joint capsule is sutured over it.
Table I. Grading of the results after operation:
After minimal follow-up of 2 years Grade
Pain
Range of motion
Excellent
None
Fllll
Good
None
Fair
Thumb stress
Poor
Pain at rest
75% < ROM of normal 50%-75% of normal < 50% of normal
Grip power Nearly fill1 Nearly full Mildly reduced Severely
and released about 3.5 cm proximal to the trapezium (Fig. 2). It is rolled up and used as a spacer by suturing it to the FCR tendon (Fig. 3). The capsule edges are approximated and sutured with 2-O absorbable sutures, and the skin incision closed, leaving a Penrose drain behind. In this stage any previous adduction contracture is corrected by appropriate soft tissue release. Postoperative
care
The hand is placed in a plaster of paris thumb spica cast for 3 weeks. The drain is removed 24 hours after the operation, and skin sutures are removed 6 to 7 days
later. The operation is usually done on an ambulatory basis, unless serious concurrent disorders exist. Clinical material
Between January 1, 1982 and December 3 1, 1987, 39 thumbs in 23 patients had operations. Ages averaged 54 years (range, 46 to 80), and 19 of 23 patients were women. The indication for surgery was severe pain located at the base of the thumb limiting the patient in activities of daily life. All patients were treated before being considered for surgery by antiinflammatory medication, as well as rest periods for a minimal duration of 6 months. Patients were not considered for surgery unless they had radiographic evidence of at least stage II osteoarthrosis of the trapeziometacqal joint.7 Eight of 39 joints had a stage II disease; 22 of 39 were stage III, and the rest were stage IV. However, the indication for operation was always clinical and not based solely on radiographs. Grip power was measured with an adjustable hand dynamometer (JAMAR Model 1, J. A. Preston Corp., Clifton, N .J.) , according to the protocol suggested by Mathiowetz et al.“’ I* Grip power was measured in the second handle position for all subjects. The average results of three consecutive measurements were recorded, provided they were within 10% of each
Vol. 16A, No. 3 May 1991
Abductor pollicis longus tendon arthroplasty
507
Table II. Grip power in patients undergoing tendon arthroplasty after a minimum follow-up of 2 years (rounded to closest pound; compared with results published by Mathiowetz et al.“) No.
Age
Sex
Hand
Mean
SD
8 of normal
5 2 7 4 6 4 4 4 1 1
45-49 45-49 50-59 50-59 60-69 60-69 60-69 60-69 70-79 70-79
F
R
F
L
F F F F M M
R L R L R L R L
56 50 49 44 42 33 73 62 35 29
12.4 14.2 9.5 8.2 10.7 10.0 13.4 12.5 9.8 8.1
90.3% 89.2% 80.1% 84.0% 80.6% 76.7% 80.7% 80.7% 68.3% 74.3%
F F
Table III. Pinch power in patients undergoing tendon atthroplasty after a minimum follow-up of 2 years (rounded to closest pound; compared with results published by Mathiowetz et al.“) Tip pinch
Key pinch
No.
&e
Sex
Hand
Mean
SD
8
Mean
SD
%
5 2 7 4 6 4 4 4 1 1
45-49 45-49 50-59 50-59 60-69 60-69 60-69 60-69 70-79 70-79
F F F F F F M M F F
R L R L R L R L R L
9 8 9 8 7 7 12 11 6 6
2.4 4.2 1.5 3.3 2.1 1.4 2.4 2.5 1.4 0.9
68% 66% 75% 73% 70% 68% 73% 72% 62% 64%
13 12 11 10 12 11 17 15 10 10
2.1 2.3 2.5 1.9 2.9 3.1 1.6 2.5 2.3 2.5
74% 72% 68% 62% 79% 75% 73% 68% 76% 80%
other. Otherwise, the test was repeated after 10 minutes. As grip power is influenced by the position of the upper limb, all patients were examined in a standardized position,“~ ‘* that is, while sitting down with the shoulder adducted, the elbow flexed to 90 degrees, the forearm and wrist in neutral position. The results were compared with those previously reported in the literature.“. I2 Pinch strength was measured with a pinch gauge (B&L Pinch Gauge, B&L Engineering, Sante Fe Springs, Calif.). Tip pinch strength, as well as key pinch and palmar pinch was measured and results were compared with previously published results. ‘I. ‘*Results were graded by one of the authors (M. A.) as shown in Table I. Results All patients in this series were followed-up by one of the authors (M. A.), and average follow-up periods
available were 53 months. A minimal follow-up period of 2 years was available for all patients. All patients reported an increase of pain in the first postoperative week. Later their condition improved rapidly, and none of them complained of pain at rest later than 1 week after surgery. One month after the operation the patients could perform light work with the hand. Grip strength was assessed both by recording of patients’ complaints and answers to directed enquiries. In addition, measurements of power-grip, as well as lateral pinch and end-to-end pinch were made during the follow-up period. Subjective grip power improved slowly after operation, with a plateau being reached after 1 year. More than 90% of patients (36 of 39) were satisfied with thumb power 1 year and later after the operation. None had to modify their daily activities because of lack of power. The results of dynamometer measurements are presented in Tables II and III. Grip power at 2 years or later after the operation averaged
508
Robinson, Aghasi, and Halperin
about 80% of the average normal result in patients of similar age. Pinch strength was somewhat weaker and averaged 65% to 70% of normal. Mobility of the joint was measured in a similar manner to that described by Weilby.3 However, since many of the patients had bilateral disease, mobility was expressed as a percentage of expected normal range of motion of the first carpometacarpal joint. The mobility is expressed as a percentage of the mobility in the unoperated hand. This method is also a problematic one since the range of motion of this joint is variable. Active mobility achieved 1 year after operation was 85% of the expected normal range (range, 73% to 100%). However, both methods yielded similar results (motion of the operated thumb as a percentage of that of the unoperated thumb averaged 92%). The major motion diminished by the operation is extension. Thumb range of abduction was not affected by the removal of one of the tendon slips of the abductor pollicis longus. Radiographically, the average scapho-first metacarpal gap was 7 mm (range, 5 to 8 m), the metacarpal was not subluxated in any of the cases. There was no correlation between gap size and final result; however, this could be due to the small number of cases with unsatisfactory results. Results were graded as excellent in 48% of patients (11 of 23), good in 35% (8 of 23), and fair in 17% (4 of 23). Hands graded as fair were so graded largely because of a mild loss of thumb power. There were few complications. No cases of infection, instability, or thumb stiffness were seen. One patient had a transient lesion of the superficial radial nerve. The nerve lesion eventually resolved completely. In two patients a fragment of the osteophyte, which commonly occurs between the first and second metacarpals, was left behind. These two patients were the only ones who later suffered from some pain during stressful thumb movements. Neither of them had any pain at rest, probably because of the small size of the fragment. The thumb range of motion was unaffected in these patients; however, they both had some loss of grip power. Discussion The principal aim of the operation is to achieve a stable and painless thumb. Additional aims are achieving reasonable mobility and strength. The advantage of interposition tendon arthroplasty is the simplicity of the operation. The various implant arthroplasties have several drawbacks. The implant life span is limited and while early results are encouraging, later deterioration is to be expected at least in some cases.‘, 5 Furthermore, cemented implants are difficult to revise after failure.‘, I3 Another potential complication of silicone
The Journal of HAND SURGERY
implants is development of silicone-induced synovitis.5 In contrast, ligament interposition arthroplasty is a surgical procedure of smaller magnitude at least according to some of the opinions expressed in the literature” as well as according to our own experience. Furthermore, as a biological material is used as a spacer, its good short-term results are expected to be long lasting. Several methods of tendon interposition arthroplasty have been described. Either the palmaris longus’ or the flexor carpi radialis tendons’. ‘O have been used as spacers. The main advantage inherent in the use of the palmaris longus tendon is its being relatively functionally unimportant to the human hand. However, it is only present in about 85% of limbs. I4 In some of the cases the tendon, although present, is not useful because of a bulky muscle belly leaving only a short length of available tendon. In some other cases the tendon is very slim. In both of these instances, accounting for 42% of cases in one series,’ not enough material is available for interposition. The use of an absorbable gelatin sponge (Gelfoam) or some other synthetic material thus becomes necessary.’ Use of the flexor carpi radialis has yielded predictably good results.‘, lo A potential disadvantage is the relatively small amount of spacer material available. This leads to a relatively small gap averaging 1.6 mm.” This might prove significant since the result of the operation has been linked to the size of the gap as seen on radiographs.” A further potential disadvantage of both of these techniques is the necessity of additional soft tissue dissection to retrieve the tendons. Weilby’ has described the imbrication of the abductor pollicis longus tendon as a salvage operation after failure of trapezia1 implants. In this procedure the tendon is sutured to the periosteum and soft tissue left in the space formerly occupied by the implant. Since this procedure achieved satisfactory results, the same author later used a modification as a primary procedure.3s I5 This procedure involved splitting a strip of the flexor carpi radialis and imbricating it around the abductor pollicis longus tendon. In up to 9% of patients de Quervain’s tenosynovitis or rupture of the abductor pollicis longus tendon caused by inflammation results. This complication could be prevented by performing a preventive first extensor compartment release.3 The procedure described by us has the advantage of preserving the flexor carpi radialis tendon. The abductor pollicis longus tendon, although classically depicted as a single thick tendon, is actually composed of two to three or more slips in most cases.“. I6 This allows the surgeon to dissect only one of the slips and use it as an interposition spacer. Leaving the rest of the tendonslips intact preserves the function of the abductor pol-
Vol. 16A, No. 3 May 1991
licis Iongus. A prophylactic first extensor compartment release is performed by us in all patients. This procedure obviates the complication of de Quervain’s tendinitis or even tendon rupture. Several important pitfalls exist in this operation. First, great care should be exercised during the initial skin incision and subcutaneous dissection not to harm the branches of the superficial radial nerve. All branches encountered should be carefully protected, since a neuroma could lead to an unsatisfactory result. Second, the radial artery should be protected and we also strongly recommend performing Allen’s test before operation to ascertain the availability of a collateral circulation. Third, the medial osteophyte present between the metacarpals should be removed because even a small fragment left behind leads to a painful and weak grip. The last important point is that the interposed tendon must be well anchored in its place. Dislocation of the tendon would lead to a smaller gap and worse clinical results. We consider this procedure successful since most patients achieve either excellent or good results. The most feared complication in this procedure is probably damage to the superficial radial nerve, with ensuing development of neuromas . This complication has been avoided in our series, as well as other series,3* ‘O by careful dissection and protection of the various branches. Though pain is usually relieved by the time of cast removal 3 weeks after the operation, improvement of grip power is slow, taking as much as 1 year. It is essential to inform the patient before the operation of the long term of gradual improvement of function. This would avoid patient disillusionment, with possible lit-
igation . REFERENCES 1. Weilby A. Surgical treatment of osteoarthritis of the
cargo-metacarpal joint of the thumb. Stand J Plast Reconstr Surg 1971;5:136-41. 2. Swanson AB, Swanson GG. Reconstruction of the thumb basal joints; development and current status of implant techniques. Clin Orthop 1987;220:68-85.
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3. Weilby A. A tendon interposition arthroplasty of the first carpo-metacarpal joint. J HAND SURG 3988;13B:423-5. 4. Hofammann DY, Ferlic DC, Clayton ML. Arthroplasty of the basal joint of the thumb using a silicone prosthesis: long term follow-up. J Bone Joint Surg 1987;69A: 993-7. 5. Pellegrini VD, Burton RI. Surgical management of basal joint arthritis of the thumb, Part I: long term results of silicone implant arthroplasty. J HAND SURG 1986&30924. 6. Gervis WI-I. Excision of the trapezium for osteoarthritis of the trapezio-metacarpal joint. J Bone Joint Surg 1949;31:537-9. 7. Dell PC, Muniz RB. Interposition arthroplasty of the trapezio-metacarpal joint for osteoarthritis. Clin Orthop 1987;220:27-34. 8. Burton RI, Pellegrini VD. Surgical management of basal joint arthritis of the thumb: Part II: ligament reconstruction with tendon interposition arthroplasty. J HAND SURG 1986;11A:324-32. 9. Eaton RG, Glickel SZ, Littler JW. Tendon interposition arthroplasty for degenerative arthritis of the trapeziometacarpal joint of the thumb. J HAND SURG 1985;lOA: 645-54. of the trapezio10. Froimson AI. Tendon arthroplasty metacarpal joint. Clin Orthop 1970;70: 191-9. 11. Mathiowetz V, Kashman N, Volland G, Weber K, Dowe M, Rogers S. Grip and pinch strength: normative data for adults. Arch Phys Med Rehabil 1985;66:69-74. 12. Mathiowetz V, Weber K, Volland G, Kashman N. Reliability and validity of hand strength evaluation. J HAND SURG 1984;9A:222-6. 13. Weilby A, Sondorf J. Results following removal of silicone trapezium implants. J HAND SURG 1978;3: 154-6. 14. Schneider LH, Hunter JM. Flexor tendons - Late reconstruction. In: Green DP, editor: Operative Hand Surgery, ed. 2. New York, 1988, Churchill Livingstone, pp 19692044. 15. Froimson A. Tenosynovitis and Tennis Elbow. In: Green DP, editor: Operative Hand Surgery, ed. 2. New York, 1988, Churchill Livingstone, pp 2117-2134. 16. Strandell G. Variations of the anatomy in stenosing tenosynovitis at the radial styloid process. Acta Chir Stand 1957;113:234-240.
