Biomechanical evaluation of intraosseous distal radioulnar joint prosthesis: A prosthesis designed based on Sauvé-Kapandji procedure

The Sauvé-Kapandji procedure for post-traumatic distal radio-ulnar arthrosis: Long-term results and analysis of risks factors for revision surgery

INTRODUCTION

The Sauvé-Kapandji (SKp) procedure is a frequently used surgery for the management of post-traumatic sequelae of the distal radio-ulnar joint (DRU). Series evaluating long-term outcomes and the risk of complications are rare. The main objective was to describe the long-term clinical and radiographic results after SKp performed in a post-traumatic context. The secondary objectives were to identify postoperative complications, surgical revisions, and their risk factors for occurrence. Our hypothesis was that although SKp confers good clinical results, identifiable risk factors for complications exist.

PATIENTS AND METHODS

This monocentric retrospective study included all patients for whom an SKp was performed in a post-traumatic context from 2008 to 2018. Pain, satisfaction, range of motion and pre- and postoperative radiographic measurements were recorded. All complications were sought and described, as well as surgical revisions. Several variables were analysed to identify risk factors for revision surgery after SKp: age, sex, initial traumatic mechanism, initial non-surgical or surgical treatment and type of surgery, time until revision surgery with SKp after the initial trauma.

RESULTS

Thirty-seven patients were included. At a median follow-up of 9.5 years (min 7.3-max 11.5), 22 patients (60%) had a VAS of 0. Range of motion was significantly improved for all the patients (p<0.001). Seventeen (46%) patients had a complication, including 5 (13.4%) cases of ossification, 4 (10.8%) cases of discomfort related to the hardware and 4 (10.8%) painful instability at the proximal ulnar stump. Thirteen (35%) patients required revision surgery. Two risk factors for revision surgery after SKp were found: time period between initial treatment and SKp of less than 7.2 months and an age of less than 53.5 years; the combination of the two factors having a sensitivity of 97.5 and a specificity of 56.7.

CONCLUSION

SKp in a post-traumatic context significantly improved range of motion and allowed pain control at long follow-up. Revision surgery seemed more frequent in patients under 53.5 years of age and when SKp was performed less than 7.2 months after the initial trauma.

LEVEL OF EVIDENCE

IV, retrospective study.

The semiconstrained DRUJ prosthesis: blessing or curse?

PURPOSE

There are numerous operative procedures to treat osteoarthritic changes or a significant instability of the distal radioulnar joint (DRUJ). The key problem of most methods is the destabilization of the forearm leading to secondary painful impingement between the radius and ulna, as well as a significant limitation of forearm rotation. The Aptis-Prosthesis designed by Scheker represents a complete substitute for the DRUJ. It is mostly used after the failure of various treatment options to solve the primary problems (arthritis, instability). We have used this type of prosthesis mostly after multiple operative treatments for more than 25 years.

METHODS

In the following retrospective study, we analyzed the data of patients that received an Aptis-prosthesis between 2016 and 2021. We have implanted this prosthesis in 13 cases (11 female, 2 male). Routinely, we document the clinical outcome concerning range of motion (ROM), grip strength, and pain according to numeric rate scaling (NRS) after more than 12 months (month 12-24). In addition, complications, osseous changes, and the rate of loosening of the prosthesis were registered. Furthermore, DASH-Score and patients ' satisfaction were evaluated. Also-as with other implants-follow-up x-rays were performed.

RESULTS

Removal or significant revision of any of the prostheses was not needed. The ROM was 68.1° ± 19.7° for pronation and 72.3° ± 20.9° for supination, grip strength amounted to 27.7 kg ± 11.0 kg equaling 83% of the contralateral side. NRS was 0 at rest and 1.2 (0-2) under weight-bearing. A lysis margin of the radial tap was noted in the radiological examination in 2 patients but without any signs of loosening. The DASH-Score added up to 31.8 ± 13.8 (13-55). All patients were satisfied or very satisfied having this implant.

CONCLUSION

The semiconstrained Aptis-prosthesis is a safe and efficient treatment option after failed DRUJ surgeries. It is striking that of the 20 implanted prostheses no significant revision or explantations were necessary over a period of 25 years.

Finite element analysis of intraosseous distal radioulnar joint prosthesis

BACKGROUND

Joint replacement is one of the options to retrieve the interosseous distal radioulnar joint (DRUJ) function. DRUJ prosthesis has recently been introduced clinically to treat DRUJ instability. This article analyzes the biomechanical behavior of the prosthesis during different loadings by the finite element method.

METHODS

CT images of a healthy 33 years old man were used to construct the three-dimensional geometry of the forearm bone. Then two models, a healthy foreman (Model A) and a damaged model with an inserted interosseous prosthesis (Model B), were constructed to analyze and compare the foreman's biomechanical behavior under different loading conditions using the finite element method. Both models were examined during pronation and supination with 500, 1000, 2000, and 5000 N.mm values. Also, both models were subjected to volar and dorsal loads with values of 10, 30, and 50 N and traction force with 100, 150, and 200 N.

RESULTS

Maximum and minimum principal stresses were evaluated for bones in all conditions, and von Mises stress was considered for the prosthesis and fixing screws. In supination, the maximum stress in Model A is significantly higher than the Model B. However, the maximum principal stress of both models is similar during volar and dorsal loading. In Model A, the maximum principal stress in traction is much smaller than in Model B. The absolute value of minimum principal stress in pronation and supination in Model B is higher than in Model A. The prostheses and screws are subjected to higher stresses during pronation than supination. Also, the amount of stress created in prostheses and screws during volar and dorsal loading is almost equal. In traction loading, screws are subjected to significantly high stresses.

CONCLUSION

Our study indicates that the interosseous DRUJ prosthesis can perform the foreman's normal daily activities. This prosthesis provides the ability similar to a normal hand.

LEVEL OF EVIDENCE

IV.