Differences in fixation stability between spacer plate and plate fixator following high tibial osteotomy.

PURPOSE: Since in vivo stability following high tibial osteotomy is unknown, surgeons customize the postoperative rehabilitation to the assumed implant stability, leaving us with numerous rehabilitation protocols. The purpose of the study is to quantify the fixation stability of different open-wedge high tibial osteotomy implants. It is hypothesized that the higher fixation stability of a plate fixator justifies early weight bearing. METHODS: In this prospective 30-subject clinical trial, fixation stability was determined over a 2-year period using radiostereometric analysis (RSA). Patients were assigned to two angle-stable osteotomy plates: a spacer plate with 6 postoperative weeks of feather-touch weight bearing versus a plate fixator with 2 postoperative weeks of feather-touch weight bearing. RESULTS: Postoperative RSA data showed a significant higher lateral translation of the distal tibia and a significantly increased subsidence, varus and internal rotation of the tibial head in the spacer plate compared to the plate fixator group. Weight bearing following spacer plate fixation induced significant micromotion 6 weeks after surgery. Three months after surgery, bone healing was achieved regardless of the used implant. CONCLUSIONS: Early weight bearing is appropriate for plate fixator fixation. The 6-week period of delayed weight bearing following spacer plate fixation is inadequate and should be prolonged presumably up to 8-10 weeks to avoid pseudarthrosis and/or recurrence of varus angulation. LEVEL OF EVIDENCE: Level II, diagnostic study--investigating a diagnostic test.

Stabilization of the pre-arthritic trapeziometacarpal joint using ligament reconstruction.

INTRODUCTION: Trapeziometacarpal pre-arthrosis is a common condition with only limited therapeutic possibilities. Eaton and Littler designed a tendon stabilization. MATERIALS AND METHODS: A series of 21 thumbs with painful carpometacarpal joints, treated with a ligament reconstruction according to Eaton and Littler, is described. Three failed and further surgery was required. The outcome of 18 is evaluated. There were 11 women, 7 men with a mean age of 33.7 years, all having stages I or II of osteoarthritis. Six (30%) had a traumatic event in their history. RESULTS: In the early stages of degenerative osteoarthritis, the overall outcome was good with a mean DASH score of 23.2. The carpometacarpal joint was stable but a 43% progression of radiographic osteoarthritic deterioration of the joint occurred. CONCLUSION: Stabilization of a painful pre-arthritic trapeziometacarpal joint is useful and reliable. A traumatic instability had worse results and probably is a contraindication to this technique.