High re-operation and complication rates 11 years after arthrodesis of the wrist for non-inflammatory arthritis.

AIMS: Plate and screw fixation has been the standard treatment for painful conditions of the wrist in non-rheumatoid patients in recent decades. We investigated the complications, re-operations, and final outcome in a consecutive series of patients who underwent wrist arthrodesis for non-inflammatory arthritis. PATIENTS AND METHODS: A total of 76 patients, including 53 men and 23 women, with a mean age of 50 years (21 to 79) underwent wrist arthrodesis. Complications and re-operations were recorded. At a mean follow-up of 11 years (2 to 18), 63 patients completed questionnaires, and 57 attended for clinical and radiological assessment. RESULTS: Of the 76 patients, 46 (60.5%) had complications, resulting in 65 re-operations, mainly related to the plate and screws. In the 63 patients who completed the questionnaires, the mean Quick Disabilities of Arm, Shoulder and Hand (QuickDASH) score was 36 (0 to 91), the mean Patient-Rated Wrist and Hand Evaluation (PRWHE) score was 40 (0 to 96), and 14 patients (22%) reported no wrist pain. Grip strength, pinch strength, and pronation and supination were significantly reduced compared with the contralateral forearm. The outcome was worse in patients who had previously undergone surgery to the wrist, and those with complications. A total of 13 are awaiting further re-operations, giving a total re-operation rate of 63% (40/63). CONCLUSION: We observed complications and re-operations throughout the follow-up period and therefore consider wrist arthrodesis to be more complicated than previously assumed. Many of the patients never got used to or accepted their stiff wrists and reported a substantial reduction in function and residual pain. Motion-sparing surgery should be offered prior to wrist arthrodesis. Cite this article: Bone Joint J 2019;101-B:852-859.

Chrome nitride coating reduces wear of small, spherical CrCoMo metal-on-metal articulations in a joint simulator.

Metal-on-metal articulations have fallen out of favour in larger joint replacements, but are still used in smaller joints. Coating the articulation has been suggested as one way of reducing wear. We compared a standard 6 mm CrCoMo articulation designed for the carpometacarpal joint of the thumb with a chromium nitride-coated version after 512,000 cycles in a joint simulator. A total of 6 articulations in each group were tested with a unidirectional load of 5 kg in Ringer's solution. We found a statistically significant reduction in weight loss, amount of metallic wear produced and volumetric wear for the chromium nitride-coated articulation. Our findings support the use of chromium nitride coating in order to minimize the amount of metallic wear produced.

Successful conversion of wrist prosthesis to arthrodesis in 11 patients.

From 2001 to 2015, 11 wrists in 11 patients with osteoarthritis of the wrist had failed wrist arthroplasties, which were subsequently converted to arthrodesis using intercalated corticocancellous autograft from the iliac crest and fixation with an arthrodesis plate or a customized peg. Clinical and radiological bone union was achieved in all the operated wrists. At final follow-up of ten patients after 6 years, they had a substantial reduction in pain and improvement in daily function and grip strength compared with those before arthrodesis. We conclude from outcomes of this series that the conversion to arthrodesis after failed wrist arthroplasty is worthwhile and reliably improve wrist function over failed wrist arthroplasty. The results suggest that the patients who will have wrist arthroplasty can be assured that in case of failure the conversion to arthrodesis will produce outcomes comparable with those after primary arthrodesis. LEVEL OF EVIDENCE: IV.

Comparison of two uncemented trapezio-metacarpal cups: a finite element study.

Trapezium components from two uncemented total joint replacements were compared in a three-dimensional finite element model. A 100 N axial and angular load was applied in a normal and an osteoporotic bone model. The axial deformation and maximum periprosthetic stress are greater for the Elektra than the Motec CMC cup. The Motec CMC design is less sensitive to changing bone quality. The Elektra cup transmits more stress to the cortical bone rim in all load conditions, but under angular loading the proportionate increase in stress is lower. The Motec CMC design distributes the stress and contact pressure more evenly, whereas the Elektra transfers most of the load to the cortical bone rim and the screw hole base. The design features that are believed to be of greatest significance for the differences are the raised centre of rotation of the Motec CMC cup and the collar acting as a lever arm.

Promising one- to six-year results with the Motec wrist arthroplasty in patients with post-traumatic osteoarthritis.

The Motec cementless modular metal-on-metal ball-and-socket wrist arthroplasty was implanted in 16 wrists with scaphoid nonunion advanced collapse (SNAC; grades 3 or 4) and 14 wrists with scapholunate advanced collapse (SLAC) in 30 patients (20 men) with severe (grades 3 or 4) post-traumatic osteoarthritis of the wrist. The mean age of the patients was 52 years (31 to 71). All prostheses integrated well radiologically. At a mean follow-up of 3.2 years (1.1 to 6.1) no luxation or implant breakage occurred. Two wrists were converted to an arthrodesis for persistent pain. Loosening occurred in one further wrist at five years post-operatively. The remainder demonstrated close bone-implant contact. The clinical results were good, with markedly decreased Disabilities of the Arm Shoulder and Hand (DASH) and pain scores, and increased movement and grip strength. No patient used analgesics and most had returned to work. Good short-term function was achieved using this wrist arthroplasty in a high-demand group of patients with post-traumatic osteoarthritis.

Is revision bone grafting worthwhile after failed surgery for scaphoid nonunion? Minimum 8 year follow-up of 18 patients.

Eighteen patients who underwent revision non-vascularized bone grafting and internal fixation after failed surgery for scaphoid nonunion were reviewed after a minimum of 8.2 years. Eleven of the nonunions were located in the middle and seven in the proximal third of the scaphoid. The mean interval between injury and the revision procedure was 6 years. Sixteen of the 18 nonunions healed, two after a third attempt. Three patients with healed nonunions and one patient with persistent nonunion required salvage procedures for progressive radiocarpal arthrosis. In the remaining 14 cases, the mean loss of wrist flexion/extension arc compared to the contralateral wrist was 36 degrees . Mean reduction of grip strength and key pinch was 9.3 kg and 0.9 kg respectively. The QuickDASH score was 18 and a visual analogue pain score was 21/100 at follow-up. Wrist degeneration increased in all but one case during the observation period. Thirteen of 16 patients with union and one patient with a persisting nonunion experienced moderate symptoms.

Energy distributions at the high-spin ferric sites in myoglobin crystals.

The orientation and temperature dependence (4.2-2.5 K) of electron paramagnetic resonance (EPR) power saturation and spin-lattice relaxation rate, and the orientation dependence of signal linewidth, were measured in single crystals of the aquo complex of ferric sperm whale skeletal muscle myoglobin. The spin-packet linewidth was found to be temperature independent and to vary by a factor of seven within the heme plane. An analysis is presented which enables one to arrive at (a) hyperfine component line-widths and, from the in-plane angular variation of the latter, at (b) the widths of distributions in energy differences between low-lying electronic levels and (c) the angular spread in the in-plane principal g-directions. The values of the energy level distributions in crystals obtained from the measurements and analysis reported here are compared with those obtained by a different method for the same protein complex in frozen solution. The spread in the rhombic energy splitting is significantly greater in solution than in the crystal.