Abstract

Abstract

Cemented total hip arthroplasty (THA) in the younger patient has historically been associated with higher wear and revision rates. We carried out a retrospective study of a prospectively collected database of patients at Wrightington hospital undergoing cemented THA under 55 years of age to determine acetabular wear and revision rates.

Between August 2005 and December 2021 a cohort of 110 patients, 56 males and 54 females, underwent Cemented Total Hip Replacement through a posterior approach. Mean age at operation was 50yrs (35–55). The mean follow up was 6 years 9 months (0–16 years). 3 patients were lost to follow-up. Of the remaining 107 patients, Conventional and cross lined polyethylene were used in 54 and 53 patients respectively. Ceramic heads were used in 102 patients. 22.225mm and 28mm heads were used in 60 and 47 patients respectively. Clinical outcomes were assessed by Merle d'Aubigne and Postel scores which showed significant functional improvement. Linear wear was measured on plain radiographs using TRAUMA CAD and cup loosening was assessed by classification of Hodgkinson et al.

No cases were revised during the observed follow up period. The mean wear rate in conventional and crosslinked polyethylene cups were 2.31mm (0.1–4.6) and 1.02mm (0.1–2.6) respectively.

Cemented THA with both conventional and crosslinked polyethylene provides excellent survival rates in adults under the age of 55 years and crosslinked polyethylene may further improve these results due to improved wear rates.

Introduction and Aims: There are more than 200,000 anterior cruciate ligament (ACL) ruptures each year in the United States. The replacements used for ACL repair do not fully recreate the ACL’s function and histological appearance. Therefore, a novel tissue-engineered ligament was designed and evaluated after ACL reconstruction in a rabbit model.

Method: Rabbits received tissue-engineered ligaments or tissue-engineered ligaments seeded with primary rabbit ACL cells. The tissue-engineered ligaments were composed of multifilament poly-L-lactide yarn (70 denier) fabricated into novel 24 yarn 3-D braids. Scaffolds were designed to be easily handled and fixed by the surgeon in ACL reconstructions using the suture over the button technique. A continuous scaffold design accommodated the flexibility of intra-articular loads and the rigours of the bone tunnels. The contralateral legs were used as controls. A key parameter for tissue ingrowth was scaffold porosity at 58 ± 9% and mode pore diameter of 183 ± 83 μm.

Results: Histological evaluations showed slow collagen tissue infiltration at the surface of the replacement at the four-week time point for both the tissue-engineered ligament and cell-seeded tissue-engineered ligament. At the 12-week time point, both replacements showed collagen ingrowth and remodelling across the entire implant occurred with a thin fibrous capsule. The cell-seeded tissue-engineered ligament demonstrated greater levels of mature collagen ingrowth and healing compared to the non-cell seeded tissue-engineered ligament. The initial tensile strength properties of the scaffold were 332 ± 20 N and 354 ± 68 MPa, which compared well to the rabbit ACL control (314 ± 66 N). The tensile properties of the tissue-engineered ligament and seeded tissue-engineered ligament at four weeks were 67% and 76%, respectively of control. The tensile properties of the biodegradable implant decreased with time for the tissue-engineered and cell seeded tissue-engineered ligament and by 12 weeks was 9% and 30% respectively, as compared to the rabbit ACL control. The 30% strength retention for the tissue-engineered ligament replacements at 12 weeks was greater than reported by others using poly(lactic acid) and polypropylene ligament augmentation devices (LAD) at 12 weeks, with values of 13% and 16% of control strength retention, respectively.

Conclusion: The results of this study demonstrate the promise of a novel cell seeded tissue-engineered ligament for anterior cruciate ligament regeneration.

Introduction and Aims: The aim of this study is to identify specific risk factors for developing haemophilia-related orthopaedic complications and to provide a qualitative and quantitative analysis of the orthopaedic management of haemophilia complications.

Method: A postal survey was sent to 48 patients on the Wellington region haemophilia database. The questionnaire covered both qualitative and quantitative questions covering the participants’ current condition and treatment, past and present orthopaedic and non-orthopaedic management, support, education, employment and leisure activities.

Results: Twenty-five patients returned the questionnaire, a response rate of 52%. Most of the participants (68%; 17/25) felt that their education had been compromised as a result of haemophilia complications. Of those participants that were 16 years or older, 68.4% (13/19) felt that their working opportunities had been compromised as a result of haemophilia complications. Despite patients less than 18 years of age receiving prophylactic Factor VIII replacement (n=7) and all patients having Factor VIII available on demand, 18 patients had significant bleeds in the previous six months. Most bleeds were into joints, 13 knees, 13 ankles, 12 elbows, six shoulders and three hips, but a significant number of intra-muscular bleeds (n=22) also occurred. There were 62 painful joints reported by 19 patients, the ankle being most common (n=21), followed by hip (n=13), elbow (n=12), and knee (n=8). Twenty-five orthopaedic operations were described by eight patients, mainly knee (n=11) and hip (n=5) replacements, and synovectomies (n=9). In the last year, two patients who have factor VIII inhibitor had been successfully operated on, one for a large pseudotumor of the thigh, and the other for contralateral hip and knee joint replacement.

Conclusion: Despite good medical management, recurrent joint bleeds are a major problem in haemophilia. Many study patients commented that orthopaedic procedures were not performed readily enough, and that by the time they received their operation, their function had deteriorated significantly.