Liner dissociation in total hip arthroplasty: a systematic review

OBJECTIVE

Liner dissociation (LD) is a rare catastrophic mechanical failure of total hip arthroplasty (THA). The study aims at reviewing the available literature regarding liner dissociations to point out their prevalence, describing any possible association and highlighting the surgical management at the time of revision.

MATERIALS AND METHODS

A systematic review of the literature was conducted from January 2002, until February 2022, according to the PRISMA guidelines. The main keywords were: "dissociation" AND "liner" OR "hip arthroplasty" OR "THA" and their MeSH terms in any possible combination. Cases of liner dissociation with all levels of evidence of any age published in indexed journals were included. The study quality of all included studies was evaluated using the MINORS criteria. The kappa (k) value was used to assess the consensus between reviewers in the selection of articles and methodological quality assessment. Finally, a sub-analysis was performed specifically concerning the elderly population.

RESULTS

Thirty-one manuscripts met the inclusion criteria of the systematic review (21 case reports and 10 case series). 124 LD in 123 patients, (53% females and 47% males) were evaluated. The overall prevalence of LD was 0.15%. The mean age at surgery was of 56.5 years (range 31-75 years). LD occurred in a primary surgery setting in 86% of the cases, at a mean time of presentation of 45.8 months after replacement surgery. 39.5% of the cups and 8.8% of the stems required revision. The mean follow-up after the revision was 18.4 months. Complications after revision occurred in 19.6% of cases, including 3 cases of re-dissociations. Re-revision was required in 13.6% of the revisions. The sub-analysis of the elderly population included 28 cases of LD identified in 10 manuscripts, with an average age of 73.5 years.

CONCLUSIONS

LD is a rare but catastrophic mechanical complication of modular THA that requires implant revision. The LD is not related to a specific prosthetic implant, liner material or design, acetabular positioning within the safe zone or age group.

Clinical and radiographic outcomes after antegrade intramedullary nail fixation of humeral fractures

INTRODUCTION

Humerus fractures are frequent, accounting for about 3-4% of all fractures in adults. Treatment for fractures of the diaphyseal and proximal meta-epiphyseal regions remains controversial: there is no unanimity in the scientific community about the superiority of surgical treatment over non-surgical treatment and which is the best between possible surgical treatments. Among the choices for surgical treatment the most commonly used implants are the locking-compression plate and the intramedullary nailing. The purpose of this study was to perform a clinical and radiographic follow-up in patients who underwent surgical procedures for reduction and osteosynthesis of proximal or diaphyseal humeral fractures by means of anterograde intramedullary nailing with a straight-shaped nail.

PATIENTS AND METHODS

A clinical and radiographic follow-up was performed in 56 patients who underwent surgical procedures for reduction and osteosynthesis of proximal or diaphyseal humeral fractures by means of antegrade intramedullary nailing using Synthes MultiLoc® system. Clinical data were collected using subjective quality of life assessment forms (SF12-v2), quality of life related to specific disabilities assessment forms (Quick-DASH, ASES score, WORC) and objective functional assessment forms (Constant-Murley score). The radiographic Follow-Up was performed at 30, 90 and 180 days from the date of the surgery.

RESULTS

Almost all patients were able to return to a satisfactory quality of life, comparable with the one before the traumatic episode. The functional results were assessed as excellent or good with almost complete recovery of the range of motion and moderate recovery of strength. The residual pain encountered was moderate or zero. The average QuickDASH score was 17.7 ± 4.3 (range 9.1 - 27.3). The average ASES score was 73.8 ± 8.1 (range 58.3 - 88.3). The average WORC score was 543.3 ± 100 [74% ± 4.8%] (range 310 - 740). The mean Constant-Murley score was 69.6 ± 4.6 (range 61 - 84). All patients had a fair or good consolidation of the fracture on radiographic examinations. The calculated RUST score was 4.2 ± 0.4 (range 4-5) 30 days after surgery, 6.1 ± 0.9 (range 4- 8) 90 days after surgery and 9.8 ± 1.5 (range 7-12) to 180 days after surgery. No major complications were found.

CONCLUSIONS

Treatment of the diaphyseal and proximal meta-epiphyseal humeral fractures with antegrade intramedullary nail provides excellent subjective and objective clinical results and good radiographic results. However, clinical studies with larger number of patients and longer follow-up are necessary.

Transiliosacral fixation using the O-ARM2® and STEALTHSTATION® navigation system

Pelvic fractures are quite uncommon, they represent only 2-8% of all fractures. Osteosynthesis with percutaneous trans-Iliosacral screw is recognized as one of the standard procedures for the treatment of unstable posterior pelvic ring lesions. Because of the high number of complications associated with the conservative treatment of these kind of lesions such as pain, limb heterometry, difficulty in walking and sexual disability, percutaneous fixation with trans-iliosacral screw has found wide use and has become very popular among orthopedic surgeons. This technique is indicated for the treatment of dislocations of the sacro-iliac joint, some types of sacral and iliac fractures or combinations of these lesions.