Flexor superficialis abductor transfer with carpal tunnel release for thenar palsy

Simultaneous Limited Incision Carpal Tunnel Release and Flexor Digitorum Superficialis Opponensplasty Using a Transverse Carpal Ligament Pulley: Surgical Technique and Case Series

Severe thenar muscle atrophy resulting in dysfunctional thumb abduction and opposition is a well-documented finding associated with long-standing severe carpal tunnel syndrome. This problem has been addressed in the past through various opposition tendon transfers. Historically, the Camitz procedure, or its modifications using the palmaris longus tendon, were recommended. However, this procedure requires a long incision in the palm, extensive dissection including the wrist area, and may not produce active thumb pronation. Our surgical technique describes an open limited palmar-only carpal tunnel release with ring finger flexor digitorum superficialis opponensplasty using a slit through the released transverse carpal ligament as a pulley and dual insertion of the tendon in both the extensor hood and the tendon of the abductor pollicis brevis. The Kapandji evaluation of thumb opposition was used to determine the outcome after surgery.

Biomimicry of the flexor digitorum superficialis: Systematic literature review

Biomimicry consists in imitating nature to solve complex human problems. The hand surgeon usually tries to copy and recreate the structure-to-function and function-to-control relationships of the native tissues after damage. With its exceptional structure and biomechanics, the flexor digitorum superficialis (FDS) has been an important source of inspiration for artificial hand system reconstruction. The present systematic literature review highlights the twenty-two artificial hand system reconstructions derived from the FDS, and presents biomimicry as an alternative approach in clinical research in hand surgery.

Maximum Palmar Abduction Angle of the Trapeziometacarpal Joint in Healthy Subjects Can Be Evaluated Accurately Using a Radiograph-Based Measurement Technique

In carpal tunnel syndrome, the abductor pollicis brevis, which is the primary muscle for the palmar abduction of the thumb, is almost inevitably impaired. The active palmar abduction of the thumb may be a better indicator of thumb disability. The authors aimed to establish a simple and accurate method to measure the angle of active palmar abduction of the thumb and to determine the maximum angle values in healthy women. Twenty-five women 20 to 21 years old with no disorder of the hand participated in this study voluntarily. Three measurement methods were tested. The first method was designed according to the Japanese Orthopaedic Association and the second method was designed according to the American Society of Hand Therapists; both use photographs to perform measurement calculations. In the third method, 2 orthopedic surgeons measured the same angle as that described in the second method on hand radiographs. Intra- and interobserver reliability were assessed for each method and described as interclass correlation coefficients. The first and third methods had strong inter- and intraobserver reliability. The second method had strong intraobserver reliability but medium interobserver reliability. The measurement obtained with the first method was significantly different from the values obtained by the second and third methods (almost double). Therefore, the authors regarded the third method as the most appropriate approach for measuring active palmar abduction of the thumb, which, in healthy individuals, yielded maximum values of 45.3°±6.4° and 44°±7° for the left hand and the right hand, respectively. [Orthopedics. 2020; 43(2):e95-e101.].

Outcomes of Endoscopic Carpal Tunnel Release With Ring Finger Flexor Digitorum Superficialis Opponensplasty in Severe Carpal Tunnel Syndrome

PURPOSE

To evaluate the outcomes of endoscopic CTR with ring finger flexor digitorum superficialis (FDS) opponensplasty for the treatment of patients with severe carpal tunnel syndrome (CTS).

METHODS

We prospectively studied 52 patients who were graded as having severe CTS by physical examination and electrodiagnostic studies and who underwent endoscopic CTR-ring finger FDS opponensplasty. Preoperative and postoperative data were collected for active perpendicular thumb abduction; Kapandji score for thumb opposition; grip, key, and tip pinch strength; Medical Research Council score on sensory and motor recovery; Semmes-Weinstein monofilament testing; thenar muscle bulk recovery; and work status.

RESULTS

Follow-up was 17.5 months on average (range, 7-34 months). Thumb abduction improved significantly from 13.2° (±4.6°) before surgery to 61.7° (±6.4°) afterward. Mean thumb opposition (as measured by Kapandji score) improved significantly from grade 1.5 to 8.7. Tip pinch strength significantly improved from 38.9% to 72.9% of the contralateral side. Medical Research Council scores improved to S3+ and S4 in 85% of patients and to M4 and M5 in 96% of patients. Sensory threshold recovery to 3.61 and 4.31 monofilament occurred in 85% of patients. We observed thenar muscle bulk recovery in 51.9% of patients. Time to return to work was 5 weeks after surgery, on average. Two patients reported scar pain, 2 reported pillar pain, and we found ring finger proximal interphalangeal joint contracture in 3.

CONCLUSIONS

Endoscopic CTR with FDS opponensplasty provides satisfactory outcomes of improved thumb abduction and opposition, sensory and motor recovery, and early return to work in patients with severe CTS.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Agenesis, functional deficiency and the common type of the flexor digitorum superficialis of the little finger: A meta-analysis

Agenesis, functional deficiency and the common type of the flexor digitorum superficialis of the little finger are reported in the literature to be highly variable with significant discrepancy between clinical and cadaveric frequencies. The aim of this systematic review was to generate overall clinical and cadaveric weighted frequencies, along with ancestry-based, side-based, sex-based and laterality-based frequencies. A systematic literature search identified 34 studies including 12,213 forearms/hands that met the inclusion criteria. Functional deficit of the FDS tendon of the little finger was significantly more prevalent among Iranian and Caucasian populations as compared to Indian, East African and Chinese populations. The weighted "clinical" frequency of functional absence of the FDS tendon of the little finger was 7.45%, while prevalence of the common type was 37.5%. The weighted "cadaveric" prevalence of muscle absence of the FDS-5 in the forearm was 2.5% while tendon absence in the hands was nil. An expanded examination technique proved to be the most accurate test for FDS function. In case of injury, inadequate knowledge of different connections or substitutions of the FDS-5 could lead to a total loss of flexion of the little finger. These findings support the hypothesis of a dual origin of the FDS-5 where the muscle portion originates in the forearm, while the tendon portion originates in the hand.

Functional pectoralis minor myocutaneous flap transplantation for reconstruction of thumb opposition: An anatomic study with clinical applications

OBJECTIVE

To develop a myocutaneous flap for reconstruction of thumb opposition function in patients with loss of the thenar muscles and skin.

METHODS

An anatomic experiment on the dimensions of the pectoralis minor muscle and its neurovascular supply in 10 adult human cadavers was conducted to evaluate the feasibility of microsurgical transplantation using part of the muscle for thumb opposition reconstruction. Based on these results, we performed surgical thenar reconstruction with a pectoralis minor myocutaneous flap in seven patients (34.7 ± 9.8 years of age) from December 2007 to October 2010.

RESULTS

The transferred muscle was reinnervated with the third lumbrical branch of the ulnar nerve. Six to twelve months after the surgery, follow-up assessment showed that all patients had recovered functional opposition of the carpometacarpal joint with survival of the skin and a muscle power of M4 to M5.

CONCLUSION

Our results support the use of this new technique for thenar and opposition reconstruction in patients with severe loss of the thenar muscles and skin and damage to the median nerve and who wish to improve the appearance of the thenar eminence.

Bilateral Absence of Flexor Digitorum Superficialis (FDS) Tendon of the Little Finger: Clinical Significance

The flexor digitorum superficialis (FDS/sublimis) is a flexor of the digits of the hand and has been reported to have varying degrees of agenesis. During routine cadaveric dissection for undergraduates at SRMS-IMS Bareilly, India, we observed bilateral absence of the FDS tendon to little finger in the upper limbs of a 45-year-old male cadaver. The muscle was normally supplied by a branch of median nerve in the forearm. Variants of the FDS muscle of the little finger have been reported in the literature. Proper knowledge of muscular variations is essential not only for anatomists but also for orthosurgeons, plastic surgeons and neurologists especially when evaluating possible tendon laceration/dysfunction. The FDS has been used as a motor for a wide variety of tendon transfer operations in the hand.

Transfer of the flexor carpi radialis to the abductor pollicis brevis tendon for the restoration of tip-pinch in severe carpal tunnel syndrome

In patients with severe thenar atrophy secondary to carpal tunnel syndrome, we hypothesize that following open carpal tunnel release, concomitant transfer of the abductor pollicis brevis (APB) origin to the flexor carpi radialis (FCR) tendon will lead to improved patient function restoring palmar abduction and thumb opposition. We evaluated 14 patients through questionnaires and seven patients through additional physical examination (thumb range of motion, ability to tip pinch, grip/pinch strength) for a mean follow-up of 2.8 years. All patients showed evidence of palmar abduction with 71% demonstrating the ability to oppose the thumb to the tip and base of the small finger. The transfer of the APB origin to the FCR tendon can restore thumb abduction and opposition for thenar paralysis secondary to severe carpal tunnel syndrome. Patients experience good functional outcomes with the majority experiencing restored thumb opposition.

Using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement to assess reporting of observational trials in hand surgery

PURPOSE

To use the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement checklist to critically evaluate the change in quality of observational trial reporting in the Journal of Hand Surgery American between 2005 and 2011.

METHODS

A cross-sectional analysis of observational studies published in the Journal of Hand Surgery American was designed to sample 2 6-month periods of publication (March 2005 to August 2005 and June 2011 to November 2011). Fifty-one items were extracted from the STROBE statement for evaluation. Overall STROBE compliance rates for articles and specific checklist items were determined. Final compliance percentages from each period were compared by Student t-testing. Changes in item compliance over time were quantified.

RESULTS

Overall compliance with the STROBE statement was 38% (range, 10%-54%) in 2005 and 58% (range, 39%-85%) for 2011 manuscripts representing a significant improvement. Seventy-five percent or greater of articles (2005/2011) provided the explicit reporting of background (100%/97%), follow-up time (85%/94%), overall interpretation of data (100%/94%), and results of similar studies (95%/89%). Twenty-five percent or less of articles provided the study design in the abstract (10%/20%), a clear description of the study's setting (10%/23%), the handling of missing data (0%/6%), the potential directions of bias (5%/11%), and the use of a power analysis (0%/17%). Eighty-six percent (44/51) of items were more frequently satisfied in 2011 articles than in 2005 publications. Absolute increases in compliance rates of 40% or greater were noted in 10 items (20%) with no worsening in compliance for an individual item over 6%.

CONCLUSIONS

The overall quality of the reporting of observational trials in the Journal of Hand Surgery American improved from 2005 to 2011. Current observational trials in hand surgery could still benefit from increased reporting of methodological details including the use of power analyses, the handling of missing data, and consideration of potential bias.

LEVEL OF EVIDENCE

Diagnostic III.

Functional pectoralis minor muscle flap transplantation for reconstruction of thumb opposition: an anatomic study and clinical applications

In this report, we present the results of an anatomic study on the dimensions of the pectoralis minor muscle and its neurovascular supply in 10 adult human cadavers, in attempt to evaluate the feasibility of microsurgical transplantation of a part of the muscle for thumb opposition reconstruction. A series of five patients consequently underwent thenar reconstruction with the pectoralis minor muscle flap from December 2004 to October 2006. The transferred muscle was reinnervated with the third lumbrical branch of the ulnar nerve. Follow-up assessment showed that the patients recovered functional opposition of carpometacarpal joint with 24 degrees of pronation, and a muscle power with M4 to M5. All patients were satisfied with the appearance of reconstructed thenar eminence. We recommend this new technique for thenar and opposition reconstruction in patients who have severe loss of thenar muscles, injury to the median nerve, and wish to improve the appearance of thenar eminence.

Outcome of tendon transfer for radial nerve paralysis: Comparison of three methods

BACKGROUND

Tendon transfer for radial nerve paralysis has a 100 years history and any set of tendons that can be considered to be useful has been utilized for the purpose. The pronator tress is used for restoration of wrist dorsiflexion, while the flexor carpi radialis, flexor carpiulnaris, and flexor digitorum superficialis are variably used in each for fingers and thumb movements. The present study was a retrospective analysis, designed to compare three methods of tendon transfer for radial nerve palsy.

MATERIALS AND METHODS

41 patients with irreversible radial nerve paralysis, who had underwent three different types of tendon transfers (using different tendons for transfer) between March 2005 and September 2009, included in the study. The pronator teres was transferred for wrist extention. Flexor carpi ulnaris (group 1, n=18), flexor carpi radialis (group 2, n=10) and flexor digitorum superficialis (group 3, n=13) was used to achieve finger extention. Palmaris longus was used to achieve thumb extention and abduction. At the final examination, related ranges of motions were recorded and the patients were asked about their overall satisfaction with the operation, their ability, and time of return to their previous jobs, and in addition, disabilities of the arm, shoulder and hand (DASH) Score was measured and recorded for each patient.

RESULTS

The difference between the groups with regard to DASH score, ability, and time of return to job, satisfaction with the operation, and range of motions was not statistically significant (P>0.05). All of the patients had experienced functional improvement and overall satisfaction rate was 95%. No complication directly attributable to the operation was noted, except for proximal interphalangeal joint flexion contracture in three patents.

CONCLUSION

The tendon transfer for irreversible radial nerve palsy is very successful and probably the success is not related to type of tendon used for transfer.

Clinical outcome of carpal tunnel release with and without opposition transfer

We studied the clinical outcome in 24 patients (25 hands) with carpal tunnel syndrome characterized by severe thenar muscle atrophy, who were treated by open carpal tunnel release alone (10 hands) or with simultaneous opposition transfer (15 hands). We also compared the surgical results in patients younger or older than 65 years. Pain and numbness improved after open carpal tunnel release but more so in younger patients. Activities of daily living also improved with and without opposition transfer; however, certain activities such as fastening hooks or buttons, using chopsticks and turning a key in a lock improved more with opposition transfer. Grip strength did not improve, with or without opposition transfer, regardless of the patients' ages. Pinch strength improved more with opposition transfer.

Pick-up test: an indication for opponensplasty in patients with severe carpal tunnel syndrome

PURPOSE

To use a pick-up test to assess thenar motor deficit and results of opponensplasty.

METHODS

Eight consecutive patients with idiopathic severe carpal tunnel syndrome and severe thenar motor deficit were identified. All were females aged 39 to 60 (mean, 53) years and right-hand dominant. The severity of thenar motor deficit was assessed using the pick-up test. Failure to pick up a coin with the thumb and index finger only in a normal pulp-to-pulp pincer grip was an indication for an opponensplasty (in addition to open carpal tunnel release) to hasten recovery of thumb abduction. Treatment outcome was assessed using the pick-up test at 6, 8, and 12 weeks.

RESULTS

Preoperatively, all patients were unable to perform the pick-up test. At postoperative 6 weeks, all patients could pick up the coin with no difficulty and were satisfied with the result of opponensplasty. There was no relapse at subsequent follow-ups and no donor-site morbidity in terms of cosmesis, scar pain or infection. Grip strength and the range of wrist motion were 63% and 92% of the normal side, respectively.

CONCLUSION

The pick-up test is a simple and reliable means of identifying those in need of an opponensplasty.