Introduction: Non-union occurs at a rate of 5–10 % following ankle and hindfoot arthrodesis, but the effect of early weight bearing on union rate in these patients has not been studied.

Materials and Method: We have looked at the union rate following ankle and hindfoot arthrodesis with an early weight bearing protocol in a single surgeon series between 2003 and 2008. Data was collected retrospectively on 108 patients with a total of 198 ankle and hindfoot joint arthrodesis.

Results: The non-union rate was 3.4% (9 in 154 joints) in the early weight bearing group and 18% (8 in 44 joints) in the late weight-bearing group. Union rate following revision surgery with bone graft was 100% in both groups.

Discussion: Early weight bearing following ankle and hind-foot arthrodesis has no adverse effect on the union rate.

Introduction: Treatment of a partial laceration in zone 2 of a flexor tendon is controversial. Although the intact part of a partially lacerated tendon is sufficient to sustain normal physiological forces, conservative management can lead to triggering, entrapment and rupture. Surgical repair is advocated for lacerations deeper than 60%. The Silfverskiold and Halsted techniques for peripheral repair use more suture material and have been shown to be stronger than a simple running suture. Currently there are no comparison of gliding resistance between different circumferential suture techniques, which is more important than tensile strength for partial lacerations.

Aim: The purpose of this study was to compare friction coefficient and gliding resistance at the flexor tendon – A2 pulley interface using three different circumferential repair techniques.

Method: Thirty long flexor tendons from long digit of turkey foot, along with the equivalent of A2 pulley were harvested. The tendons were lacerated to 50% and ten each were subjected to a Silfverskiold, Halsted or a running suture. All experiments were carried out for intact and lacerated tendon at 30, 50 and 70 degrees of flexion and two load settings of 2 N and 4 N. Gliding resistance was measured as the difference between forces recorded at the two ends of the tendon and the friction coefficient was measured using this formula, μ = Ln[(F2/F1)]/Ø.

Results: The Halsted repair was associated with a 100% increase in gliding resistance and friction coefficient relative to the intact tendon, compared to 80% for the Sil-fverskiold repair and 60% for a running suture (p=0.05). The running suture was technically the easiest.

Conclusion: We recommend a simple running suture for peripheral repair of partial flexor tendon lacerations, where surgical repair is advocated.

Treatment of a partial laceration in zone two of a flexor tendon remains controversial. The intact part of the tendon can sustain forces of normal un-resisted motion, and repaired partially treated tendons can actually be weaker than un-repaired ones. Trimming these lacerations has been shown to be beneficial in partially lacerated tendons with triggering or entrapment.

The purpose of this study is to observe the behaviour of a partially lacerated and subsequently trimmed tendon under strain, and measure their friction coefficient at different flexion angle and load. Ten long flexor tendons from long digit of turkey foot, along with the equivalent of A2 pulley were used. All experiments were carried out for intact, lacerated (50%) and trimmed tendon at 10, 30, 50 and 70 degrees of flexion and two load settings of 200 and 400g.

The friction forces were measured by the difference between the two load transducers and the friction coefficient was measured using this formula, μ = Ln[(F2/F1)]/Ø.

Friction coefficient (μ), Tension forces (F2 and F1), arc of tendon and pulley contact (Ø).

Results: Friction coefficient increased significantly by three folds (0.3) after laceration compare with intact tendon (0.12) at both loads. This was reduced significantly after trimming the tendon but the friction coefficient was still approximately twice the value of the intact tendon (0.2).

Triggering was noticed in all tendon lacerations. Triggering was reduced after trimming in 10 and 30 degrees of flexion but increased markedly at 50 and 70 degrees of flexion associated with tendon fragmentation at the trimmed area.

Trimming partially lacerated flexor tendons will reduce the gliding resistance of the tendon through the pulley but this can lead to further fragmentation and triggering at higher flexion degrees and loads.

Non-union is a potential complication following hindfoot arthrodesis and occurs at a rate of 5–10% as reported in the literature. Following the procedure, patients are usually kept non-weight bearing (NWB) for 6–8 weeks followed by protected full weight bearing (FWB) for further 6 weeks. Based on radiological and clinical evidence of bony union at 12 weeks patients are allowed to mobilise FWB without protection. The aim of this study is to evaluate the effect of early post operative weight bearing on the union rate, following hindfoot arthrodesis.

In this retrospective study data was collected on patients who had hindfoot arthrodesis from 2003 to 2008 by a single surgeon. Two post operative mobilisation protocols were used and the union rates were compared. Protocol 1: 6 weeks Non weight bearing (NWB), 3 weeks partial weight bearing (PWB), 3 weeks full weight bearing (FWB) in plaster. Protocol 2: 2 weeks NWB, 4 weeks PWB, 6 weeks FWB in plaster.

One hundred and twenty-nine hindfoot joint arthrodesis were performed in 73 patients. Non-union rate was 1% (1 in 95 joints) in early weight bearing group and 20% (7 in 34 joints) in late weight bearing group. Union rate following the revision surgery with bone graft was 100% in both groups.

Early weight bearing following hindfoot arthodesis is safe, provides a more comfortable mobilisation for the patient and has no adverse effect on the union rate.

Introduction: Treatment of a partial laceration in zone 2 of a flexor tendon is controversial. Although the intact part of a partially lacerated tendon is sufficient to sustain normal physiological forces, conservative management can lead to triggering, entrapment and rupture. Surgical repair is advocated for lacerations deeper than 50%. The Silfverskiold circumferential techniques is stronger than the Halsted repair or a running suture, but there is currently no comparison of gliding resistance, which is probably more important than tensile strength for partial lacerations.

Aim: The purpose of this study was to compare three different circumferential repair techniques in terms of coefficient of friction and gliding resistance at the flexor tendon – A2 pulley interface.

Method: Thirty long flexor tendons from long digit of turkey foot, along with the equivalent of A2 pulley were harvested. The tendons were lacerated to 50% and ten each were subjected to a Silfverskiold, Halsted or a running suture. All experiments were carried out for intact and lacerated tendon at 30, 50 and 70 degrees of flexion and two load settings of 2 N and 4 N. Gliding resistance was measured as the difference between forces recorded at the two ends of the tendon and the friction coefficient was measured using this formula, μ = Ln[(F2/F1)]/Ø.

Results: The gliding resistance and friction coefficient with the Silfverskiold technique were 1.3 times that of the other two techniques (P< 0.001).

Conclusion: The Silfverskiold technique leads to higher friction at the tendon-pulley interface and may not be an ideal treatment for partial flexor tendon lacerations.

We carried out lacerations of 50%, followed by trimming, in ten turkey flexor tendons in vitro and measured the coefficient of friction at the tendon-pulley interface with loads of 200 g and 400 g and in 10°, 30°, 50° and 70° of flexion. Laceration increased the coefficient of friction from 0.12 for the intact tendon to 0.3 at both the test loads. Trimming the laceration reduced the coefficient of friction to 0.2. An exponential increase in the gliding resistance was found at 50° and 70° of flexion (p = 0.02 and p = 0.003, respectively) following trimming compared to that of the intact tendon.

We concluded that trimming partially lacerated flexor tendons will reduce the gliding resistance at the tendon-pulley interface, but will lead to fragmentation and triggering of the tendon at higher degrees of flexion and loading. We recommend that higher degrees of flexion be avoided during early post-operative rehabilitation following trimming of a flexor tendon.

Introduction: Non-union is a potential complication following hindfoot arthrodesis and occurs at a rate of 5–10% as reported in the literature. Following the procedure, patients are usually kept non-weight bearing (NWB) for 6–8 weeks followed by protected full weight bearing (FWB) for further 6 weeks. Based on radiological and clinical evidence of bony union at 12 weeks patients are allowed to mobilise FWB without protection.

Aim: The aim of this study is to evaluate the effect of early post operative weight bearing on the union rate, following hindfoot arthrodesis.

Method: In this retrospective study data was collected on patients who had hindfoot arthrodesis from 2003 to 2008 by a single surgeon. Two post operative mobilisation protocols were used and the union rates were compared.

Protocol 1: 6 weeks NWB, 3 weeks partial weight bearing (PWB), 3 weeks FWB in plaster.

Results: 128 hindfoot joint arthrodesis were performed in 73 patients. Non-union rate was 2%(1 in 44) in early weight bearing group and 20% (4 in 16) in late weight bearing group. Union rate following the revision surgery with bone graft was 100% in both groups.

Conclusion: The union rate following hindfoot surgery significantly improves (p=0.01) with early post-operative weight bearing.