Pyrocarbon proximal interphalangeal joint arthroplasty: minimum two-year follow-up.

PURPOSE: To report the outcome and complications from pyrocarbon proximal interphalangeal (PIP) joint arthroplasty at a minimum of 2 years of follow-up. METHODS: A retrospective case review was performed on 72 patients with an average age of 57 years, and a total of 97 pyrocarbon PIP joint arthroplasties. Patient demographics, diagnosis, implant revisions, and other repeat surgeries were recorded. Subjective outcome was evaluated at latest follow-up with the Disabilities of the Arm, Shoulder, and Hand score; Patient Evaluation Measure; and visual analog scores of pain, satisfaction, and appearance. Objective outcomes included PIP joint range of motion, grip strength, and radiographic assessment of alignment and loosening. RESULTS: The principal diagnosis was primary osteoarthritis in 43 patients(60%), posttraumatic arthritis in 14 (19%), rheumatoid arthritis in 9 (13%), and psoriatic arthritis in 6 (8%). The average follow-up was 60 months (range, 24-108 mo). Twenty-two of 97 digits (23%) had repeat surgery without revision, and 13 digits (13%) had revision at an average of 15 months. There were no significant differences in preoperative and postoperative range of motion. The average Disabilities of the Arm, Shoulder, and Hand score was 22, and the average pain score was zero. Implant migration and loosening was observed but was not related to clinical outcome or revision. CONCLUSIONS: The survival of pyrocarbon PIP joint arthroplasty was 85% (83 of 97) at 5 years of follow-up, with high patient satisfaction. Patients should be advised that the procedure achieves good relief of pain but does not improve range of motion. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Skin tension in the aetiology of Dupuytren's disease; a prospective trial.

Tension in the palmar fascia has been proposed as a factor causing Dupuytren's disease. If tension does stimulate the growth of new Dupuytren's tissue, relieving longitudinal tension should reduce the recurrence rate following surgery. Thirty patients with palmar Dupuytren's contracture of a single ray that affected only the metacarpophalangeal joint were divided into two groups. Both groups had a fasciotomy: one group through a transverse incision that was closed directly and the other through a longitudinal incision with Z-plasty closure. Half the patients (seven of 14) who had direct closure had recurrence at 2 years as compared to two of the 13 in the Z-plasty group. The trial was stopped at the interim analysis stage due to the high recurrence rate in the first group. These results are consistent with the tension hypothesis for the aetiology of Dupuytren's disease.

In-vivo confirmation of the use of the dart thrower's motion during activities of daily living.

The dart thrower's motion is a wrist rotation along an oblique plane from radial extension to ulnar flexion. We report an in-vivo study to confirm the use of the dart thrower's motion during activities of daily living. Global wrist motion in ten volunteers was recorded using a three-dimensional optoelectronic motion capture system, in which digital infra-red cameras track the movement of retro-reflective marker clusters. Global wrist motion has been approximated to the dart thrower's motion when hammering a nail, throwing a ball, drinking from a glass, pouring from a jug and twisting the lid of a jar, but not when combing hair or manipulating buttons. The dart thrower's motion is the plane of global wrist motion used during most activities of daily living. Arthrodesis of the radiocarpal joint instead of the midcarpal joint will allow better wrist function during most activities of daily living by preserving the dart thrower's motion.

Reproducibility of radiographic classification of scapholunate advanced collapse (SLAC) and scaphoid nonunion advanced collapse (SNAC) wrist.

The aim of this study was to measure inter- and intra-observer agreement on the radiographic classification of scapholunate advanced collapse (SLAC) and scaphoid nonunion advanced collapse (SNAC) wrist. Radiographs of 41 patients with SLAC wrist and 47 patients with SNAC wrist were graded on two separate occasions by four orthopaedic consultants specializing in hand and wrist surgery. Inter-observer agreement was evaluated using the multi-rater kappa value. Landis and Koch criteria were used to assess the level of agreement. Intra-observer agreement was tested by re-grading the radiographs after an interval of 2 to 4 weeks and calculating the weighted kappa value. For SLAC wrist, the inter-observer agreement was moderate (kappa value = 0.59) and intra-observer agreement substantial (kappa value = 0.65). For SNAC wrist, the inter-observer agreement was slight (kappa value = 0.20) and intra-observer agreement was fair (kappa value = 0.29). Radiographic classification of SLAC wrist has moderate reliability and reproducibility, whereas classification of SNAC wrist has limited reliability.

Survivorship of the Neuflex silicone implant in MCP joint replacement.

The Neuflex silicone metacarpophalangeal (MCP) joint replacement has previously been shown to provide improved movement, particularly flexion, when compared with the Swanson implant. In this study, we reviewed the outcome of 237 Neuflex implants in 66 patients with a follow-up of up to 7 years. Kaplan-Meier analysis using revision as the end stage revealed survival at 7 years to be 88%. If however an implant fracture, as seen radiographically, is taken as the end point, the survivorship drops to 68% at 7 years. These figures are comparable with a similar analysis for the Swanson implant. We conclude that the improved range of motion of the Neuflex implant demonstrated previously does not result in either a higher or a lower revision or implant fracture rate when compared with the Swanson implant.

Tendon graft--ulna fixation in distal radio-ulnar joint stabilisation; biomechanical comparison of three graft-bone fixation methods.

A common distal radio-ulnar joint (DRUJ) stabilisation procedure uses a tendon graft running from the lip of the radial sigmoid notch to the ulnar fovea and through a bony tunnel to the ulnar shaft, before being wrapped round the distal ulna and sutured to itself. Such graft fixation can be challenging and requires a considerable tendon length. The graft length could be reduced by fixing the graft to the ulna using a bone anchor or interference screw. The aim of this study was to compare the strength of three distal ulna graft fixation methods (tendon wrapping and suturing, bone anchor and interference screw). Four human cadaveric ulnae were used. A tendon strip was run through a tunnel in the distal ulna and secured by: (1) wrapping round the shaft and suturing it to itself, (2) a bone anchor and (3) an interference screw in the bone tunnel. Load to failure was determined using a custom-made apparatus and an Instron machine. Maximum failure load was highest for the bone anchor fixation (99.3 +/- 23.7 N) followed by the suturing (96.2 +/- 12.1 N), and the interference screw fixation (46.9 +/- 5.6 N). There was no significant difference between the tendon suturing and bone anchor methods, but the tendon suturing was statistically significantly higher compared to the interference screw (P = 0.028). In performing anatomical stabilisation of the DRUJ fixation of the tendon graft to the distal ulna with a bone anchor provides the most secure fixation. This may make the stabilisation technique less demanding and require a smaller tendon graft.