Aims

Our primary aim was to establish the proportion of female orthopaedic consultants who perform arthroplasty via cases submitted to the National Joint Registry (NJR), which covers England, Wales, Northern Ireland, the Isle of Man, and Guernsey. Secondary aims included comparing time since specialist registration, private practice participation, and number of hospitals worked in between male and female surgeons.

Introduction. While advances in joint-replacement technology have made total ankle arthroplasty a viable treatment for end-stage arthritis, revision rates for ankle replacements are higher than in hip or knee replacements [1]. The questions asked in this study were (1) what retrieved ankle devices demonstrate about ankle arthroplasty failures, and (2) how do these failures compare to those seen in the hip and the knee?. Materials and Methods. An IRB-approved retrieval laboratory received retrieved polyethylene inserts and surgeon-supplied reason for revision from 70 total-ankles (7 designs, including five currently-marketed designs) from 2002 to the present. All retrievals were rated for clinical damage. Polyethylene inserts received six months or less after retrieval (n=45) were analyzed for oxidation using Fourier Transform Infrared (FTIR) spectroscopy, reported as maximum ketone oxidation index [2]. Insert sterilization method was verified using trans-vinylene index [3]. Oxidation measured in the 45 ankle inserts versus their time in vivo was compared to oxidation rates previously published for gamma-sterilized hip and knee polyethylene retrievals [6]. Statistical analysis was performed using IBM SPSS v.22. Results. The ankle devices were retrieved most commonly for loosening (n=22) followed by polyethylene fracture (n=9). These failure modes occurred after statistically different in vivo time (loosening: mean=4.4±3.6 years; polyethylene insert fracture: mean=9.5±4.1 years; p=0.002). Presence of clinical fatigue (cracking and/or delamination) was identified in 24 of the 70 retrieved inserts, and its presence correlated with in vivo time (Spearman's rho =0.449, p<0.001). Thirteen of these fatigued inserts were analyzed by FTIR. TVI analysis confirmed the sterilization method of the fatigued inserts: 12 gamma, 1 non-gamma sterilized. All 13 fatigued inserts had maximum ketone oxidation index (KOI) of 1.2 or higher. Presence of fatigue correlated with measured oxidation (Spearman's rho =0.685, p<0.001). Six of the 9 inserts that fractured in vivo were analyzed by FTIR. All were gamma-sterilized, and all had oxidation of 1.2 or higher. Oxidation rate determined for most of the 45 ankle inserts was at or above oxidation rates previously published for gamma-sterilized hip and knee polyethylene retrievals [6]. Discussion. This retrieval study concurs with the ankle arthroplasty literature that loosening is the most common reason for ankle revision [4]. Ankle inserts retrieved as a result of implant loosening had lower oxidation and no fatigue damage resulting from their shorter in vivo time. Fatigued and/or fractured inserts were in vivo for longer times, allowing more oxidation to occur. The effect of oxidation on polyethylene tensile strength and ductility has been reported for tibial inserts [5]. Oxidation above the critical value [5] has a dramatic effect on the ability of the polyethylene to resist fatigue damage and fracture, since the toughness of the polyethylene drops to near zero. All fatigued and fractured ankle inserts had oxidation that exceeded this critical oxidation. Most ankle inserts, whether gamma or non-gamma sterilized, oxidized at or above the oxidation rates previously published for gamma-sterilized hip and knee polyethylene retrievals [6]

We present our experience of using tension band plates to achieve guided growth in children for correction of calcaneus deformity of the ankle. 11 consecutive patients (13 ankles) fulfilled the inclusion criteria over a 4-year period. All underwent surgical treatment using a flexible two hole plate and screws on the posterior aspect of distal tibial physis. Measurements were done on preoperative, intraoperative screening and 1-year post operative plain AP and lateral ankle radiographs. The anterior distal tibia angle (ADTA), lateral distal tibial angle (LDTA) and screw divergence angle (angle subtended by lines passing through the long axis of the screws) were used to assess the deformity correction. A 2 tailed student t-test was carried out on the initial and 1-year post-op measurements to determine statistical significance with a p value <0.05 considered as significant. There were 10 residual clubfoot deformities, 2 post-traumatic deformities and 1 spinal tumor causing deformity. The average age of the patients was 10 years 5 months (range 4 to 13 years). There were 9 males and 2 females. The ADTA showed a statistically significant change with a p value of 0.0008 with a mean correction of 8.6 degrees (range of 2.3 to 15.6 degrees). The SDA demonstrated a mean correction of 15.4 degrees (range 0.3 to 41.8 degrees), p=0.002. The LDTA did not change significantly (p= 0.08), thus confirming no coincidental coronal plane deformity had occurred. 5 ankles required revision of fixation due to metalwork reaching its maximum limit of divergence at an average of 1 year. 2 ankles had screw pulled out due to osteolysis around the screw. There were no cases of infection. We report satisfactory short-term results of correction of calcaneus deformity using a flexible tension band plate and screws system