1. Rupture of the Flexor Pollicis Longus Tendon after Volar Plating of the Distal Radius: Reconstruction with Palmaris Longus Tendon Interposition Graft.
Joris Duerinckx MD, Pieter Berger MD
Division of Orthopaedic Surgery, Ziekenhuis Oost-Limburg, Belgium
Introduction
Chronic ruptures of the flexor pollicis longus (FPL) tendon are rare. The introduction of angular stable volar plating to treat distal radius fractures in 2000 (1) has been associated with an increasing incidence of ruptures of the FPL-tendon and it is a major complication of this treatment (2,3,4). The main contributing factor is flexor tendon wear over the distal edge of a plate if this is placed distal to the watershed line (5). Preferred management for chronic FPL tendon ruptures has not been determined yet as only a few reports present the outcome of their surgical treatment in detail (3,4,6,7). The purpose of this study was to evaluate the outcome of a series of 4 one-stage reconstructions of the FPL tendon with a free palmaris longus (PL) interpositional tendon graft.
Introduction

2. Methods Methods Case Age (years) Side Sex 1 52 L Male 2 79 R Female 3
We examined 4 patients with a spontaneous rupture of the FPL-tendon due to friction against a malpositioned volar distal radius plate. All tendons were repaired with an interposition autograft of the PL tendon. Mean follow-up was 19.8 months (Range 8-31). Clinical result was assessed by measuring thumb mobility, pinch and grip strength. Results were compared between operated and non-operated hands. Functional outcome was evaluated with the DASH-score and pain with the VAS score. Statistical analysis was performed using the non-paired Student’s t-test. The study was approved by the institutional ethical review committee.
Methods
4 patients with spontaneous FPL rupture after volar plating
FPL reconstruction with palmaris longus graft
- Clinical result
- DASH-score
- VAS
Case
Age (years)
Side
Sex 1 52 L
Male 2 79 R
Female 3 76 4 57

3. Surgical technique Surgical Technique Results Results
Volar henry approach. Frayed ends of the FPL tendon are held in continuity by pseudotendon that was debrided (Fig. 1).
Removal of hardware.
Harvest PL tendon by transection at the volar wrist crease and proximal retrieval at musculotendinous junction with a tendon stripper.
Identification of distal end of the FPL tendon: Brunner-incision in the thenar eminence (Fig. 4).
Pass the PL graft through the carpal tunnel (Fig. 5). The presence of the distal stump of the FPL-tendon up to the volar wrist crease facilitates passing the graft in the correct position
Fix the PL graft to the distal tendon stump with a Pulvertaft tendon weave repair using at least 4 transverse passes. At every pass fix the tendon graft with a matress stitch with Fiberloop 4/0 suture (Arthrex, Naples, Florida, USA). Fix the graft proximally using the same technique.
Tension the graft in slightly more flexion than the contralateral thumb, taking contracture of the FPL muscle belly into account. With the wrist in neutral position the thumb pulp touches the base of the ring finger (Fig. 6). Test wrist tenodesis effect to ensure proper gliding of the tendon graft (Fig. 7-8).
Postoperatively: dorsal blocking splint was applied, immobilizing the wrist and thumb in moderate flexion. Start three to five days later with a standard Kleinert type passive flexion and active weeksextension rehabilitation protocol with protective bracing for 6.
Surgical Technique
Results
Mean active interphalangeal (IP) joint flexion was 44° (range 15-60) for the operated thumb and 80° (range ) for the opposite thumb. This is a significant reduction of IP joint flexion (P = 0.02). Mean Kapandji thumb opposition score was 8/10 (range 5-9) for the operated thumb and 10/10 for the other side, also a significant difference (P = 0.03). Mean power grip of the operated hand was 32 kg (20-46) and is comparable to the contralateral hand (mean 32 kg, range 24-48) (P 0.5). Mean key pinch strength of the operated hand was 7 kg (6-7.5) and is comparable to the other side where we measured 8 kg (5.5-13) (P 0.25). The mean DASH score was 14 (4.5-28) points. The mean Visual Analogue Scale for pain was 2.5/10 (1-5).
Results

4. Discussion and conclusion
Case
IP 45° ext
(degrees)
MCP 45° ext
Retropulsion
(mm)
1st Webspace opening (degrees)
Kapandji
Score
Keypinch strength
(kg)
Grip strength I UI 1 55 60 70 30 52 85 9 10
7.5 13 46 48 2 15 40 50 35 75 5
5.5 20 24 3
100 80 6 31 25 4 45 90 8
Clinical results including mobility and force listed per patient. Legend: I: involved side, UI: uninvolved side
Conclusions
Advantages of the PL as graft donor: suitable length, of suitable diameter and conveniently near.
To our knowledge this is the first study that reports the results of a series of FPL reconstructions in detail.
Although IP flexion of the thumb did not return to normal after surgery, patients reported excellent functional results.
The mean DASH score of 14 in our study population is comparable with the mean DASH score of 13 points that is found in the normal population (8).
In our series grip and key pinch strength were unaffected.
Shortcomings of this study are the retrospective design, the lack of a control group and the small number of patients.
We conclude that FPL tendon rupture is a severe complication after volar plating of distal radius fractures. Preferred treatment of FPL rupture in this indication has not been determined yet and not much is known about outcome of eventual surgical treatment. FPL reconstruction with PL autograft is a valuable treatment option that can provide good functional recovery of hand function.
Discussion and conclusion
References
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