As the numbers of revision total knee arthroplasty (RTKA) rise, we continually need current information regarding the etiology/modes of failure and functional disability of patients presenting for RTKA. We used a prospective cohort study to assess these fundamental aspects of RTKA.

290 consecutive subjects presenting for RTKA had relevant clinical information, including modes of failure, collected from surgeon-completed documents. Patients themselves also completed quality of life and functional questionnaires, including the SF-36 and WOMAC Osteoarthritis Index.

Mean patient age was 68.6 years (55 to 79 years). Mean SF-36 and WOMAC score at baseline indicated significant functional disability. The mean time from primary procedure to RTKA was 7.9 years (6 months to 27 years). Our series included 31 percent ‘early’ (under 2 years) revisions and 69 percent ‘late’ revisions. Sepsis was the cause of 10.4 percent revisions. The tibia needed revision in 78 percent, femur in 71 percent and patella in 31 percent of cases. The predominant modes of failure (non-exclusive frequency values as patients could have more than one cause) were (in percentages): instability (28.9), malalignment (27.5), tibial osteolysis (27.5), polyethylene wear (24.5), femoral osteolysis (22.5) and tibial loosening (22.2).

These patients are relatively young, and considerably disabled by their failed primary procedure. Many modes of failure are within surgical control and direct us toward improved techniques and approaches. Other modes confirm the need for continued development of implants and materials. Information gained here will allow better formulation of measures and resource allocation that may prevent RTKAs.

To identify mechanisms of failure in plate and nail fixation in proximal humerus fractures. 5% of the proximal humerus fractures need surgical fixation, which is carried out, principally, by open reduction and internal fixation or closed reduction and intramedullary nailing. Fixation failure remains a problem. This study answers the mode of failure of these implants regardless of the fracture personality. In-vitro testing of proximal humerus fixation devices was undertaken in 30 simulated osteoporotic bone models. Fracture-line was created at the surgical neck of humerus in all samples and fixed with five fixation devices; three plating and two nailing devices. The samples were subjected to failure under compression and torque. Failure was achieved in all models. Three failure patterns were observed in torque testing:

The two conventional plates Cloverleaf and T-plate behaved similarly, failing due to screw pull-out from both the proximal and distal fragment with a deformed plate.

The failure mode is dependent on implant properties as well, independent of the fracture personality. It is important to recognise the potential points of failure (proximal or distal fragment) when making the choice of implant to avoid fixation failure.

This study aims to compare the biomechanical properties of the “Double Lasso-Loop” suture anchor (DLSA) technique with the commonly performed interference screw (IS) technique in an ex vivo ovine model. Fourteen fresh sheep shoulder specimens were used in this study. Dissection was performed leaving only the biceps muscle attached to the humerus and proximal radius before sharply incised to simulate long head of biceps tendon (LHBT) tear. Repair of the LHBT tear was performed on all specimens using either DSLA or IS technique. Cyclical loading of 500 cycles followed by load to failure was performed on all specimens. Tendon displacement due to the cyclical loading at every 100 cycles as well as the maximum load at failure were recorded and analysed. Stiffness was also calculated from the load displacement graph during load to failure testing. No statistically significant difference in tendon displacement was observed from 200 to 500 cycles. Statistically significant higher stiffness was observed in IS when compared with DSLA (P = .005). Similarly, IS demonstrated significantly higher ultimate failure load as compared with DSLA (P = .001). Modes of failure observed for DSLA was mostly due to suture failure (7/8) and anchor pull-out (1/8) while IS resulted in mostly LHBT (4/6) or biceps (2/6) tears. DSLA failure load were compared with previous studies and similar results were noted. After cyclical loading, tendon displacement in DLSA technique was not significantly different from IS technique. Despite the higher failure loads associated with IS techniques in the present study, absolute peak load characteristics of DLSA were similar to previous studies. Hence, DLSA technique can be considered as a suitable alternative to IS fixation for biceps tenodesis

Aims. Retrospective review of a consecutive series of 1,168 total ankle replacements (TAR) performed at Wrightington, to analyse modes of failure and clinical outcomes following TAR failure. Methods. All patients undergoing TAR between November 1993 – June 2019 were collated (4–25 year follow-up; mean 13.7 years). 6 implants were used (300 STAR, 100 Buechal Pappas, 509 Mobility, 118 Zenith, 41 Salto and 100 Infinity). 5 surgeons, all trained in TAR, performed the surgery. Modes of failure were collated and clinical and radiological outcomes recorded for the revisional surgery following failure of the TAR. Results. 156 (13.4%) TARs failed (47STAR 15.6%, 16BP 16%, 77Mobility 15.1%, 6Salto 14.6%, 10Zenith 8.5% and 0Infinity 0%). Mean time to failure 5.8 years (0.1- 21.4 years). The 4 most common modes of failure were 44.9% aseptic loosening, 11.5% gutter pain, 10.9% infection and 10.3% recurrent edge loading. 50 underwent conversion to tibiotalocalcaneal (TTC) fusion with nail with 9 (18%) failing to fuse. 31 underwent revision TAR with 2 (6.5%) subsequently failed. 22 underwent ankle fusion with 10 (45%) failing to fuse. 21 underwent polyethylene exchange of which 8 (38%) had further poly failure. 20 (12.8%) were managed conservatively, 2 (1.3%) required below knee amputation and 6 were listed but lost to follow-up. 81 of the 1168 (7%) consecutive cohort were lost to follow-up. Conclusions. 13.4% of the TAR cohort have failed at average follow-up 13.7 years. There was no difference in failure modes across the implant designs. Whilst the fixed bearing has the shortest follow-up, it may be performing better as there have been no failures so far. Prior to October 2016, most revisions were to fusion (TTC 18% failure rate, ankle 45% failure rate), whereas post 2016, 57% patients elected for revision TAR (6.5% failure)

The Adams-Berger reconstruction is an effective technique for treating distal radioulnar joint (DRUJ) instability. Graft preparation techniques vary amongst surgeons with insufficient evidence to support one technique over another. Our study evaluated the biomechanical properties of four graft preparation techniques. Extensor tendons were harvested from fresh frozen porcine trotters obtained from a local butcher shop and prepared in one of three configurations (n=5 per group): tendon only; tendon prepared with non-locking, running suture (2-0 FiberLoop, Arthrex, Naples, FL) spaced at 6 mm intervals; and tendon prepared with suture spaced at 12 mm intervals. A fourth configuration of suture alone was also tested. Tendons were allocated in a manner to ensure comparable average diameters amongst groups. Biomechanical testing occurred using custom jigs simulating radial and ulnar tunnels attached to a Bose Electroforce 3510 mechanical testing machine (TA Instruments). After being woven through the jigs, all tendons were sutured end-to-end with 2-0 PROLENE suture (Ethicon). Tendons then underwent a staircase cyclic loading protocol (5-25 Newtons [N] at 1 hertz [Hz] for 1000 cycles, then 5-50 N at 1 Hz for 1000 cycles, then 5-75 N at 1 Hz for 1000 cycles) until graft failure; if samples did not fail during the protocol, they were then loaded to failure. Samples were visually inspected for mode of failure after the protocol. A one-way analysis of variance was used to compare average tendon diameter; post-hac Tuhey tests were used to compare elongation and elongation rate. Survival to cyclic loading was analyzed using Kaplan-Meier survival curves with log rank. Statistical significance was set at a = 0.05. The average tendon diameter of each group was not statistically different [4.17 mm (tendon only), 4.33 mm (FiberLoop spaced 6 mm), and 4.30 mm (FiberLoop spaced 12 mm)]. The average survival of tendon augmented with FiberLoop was significantly higher than tendon only, and all groups had significantly improved survival compared to suture only. There was no difference in survival between FiberLoop spaced 6 mm and 12 mm. Elongation was significantly lower with suture compared to tendon augmented with FiberLoop spaced 6 mm. Elongation rate was significantly lower with suture compared to all groups. Modes of failure included rupture of the tendon, suture, or both at the simulated bone and suture and/or tendon interface, and elongation of the entire construct without rupture. In this biomechanical study, augmentation of porcine tendons with FiberLoop suture spaced at either 6 or 12 mm for DRUJ reconstruction significantly increased survival to a staircase cyclic loading protocol, as suture material was significantly stiffer than any of the tendon graft configurations

The Mathys. ¯. finger joint replacement system offers a novel fixation method into the proximal and distal medullary canals and a semi-constrained articulation. This comprises a separable, form-fit joint with a distal/proximal play of 0.7 mm, a lateral excursion of 10°, and rotation of up to 6°. This has theoretical advantages of increased radio-ulnar stability, preventing ulnar drift in patients with rheumatoid disease, and enhanced osseointegration offering implant longevity. In our unit, however, high failure rates were noted, prompting a review of cases to quantify our suspicions. Case notes of all patients who underwent finger joint replacement using the Mathys. ¯. implant between 1999 and 2005 were retrieved. Twenty-two devices were implanted by a single surgeon during this period. Four were in finger proximal interphalangeal joints, 17 in finger metacarpophalangeal joints and one in a thumb carpometacarpal joint (CMCJ). Indications for joint replacement included sixteen for rheumatoid arthritis (RA) and five for post-traumatic joint problems. The only thumb CMCJ was replaced for primary osteoarthritis. Patients were reviewed regularly and implant performance assessed critically along with survival of the implant to revision, infection or death of the patient. Mean follow up was 30 months. Sixteen implants failed including the only thumb CMCJ. Modes of failure were rotation (11), poor range of motion (two), infection (two) and dislocation (the CMCJ). Similar ball and socket designs for uncemented thumb CMCJ replacement, such as the Ledoux prosthesis, have previously shown poor survival and have been withdrawn from the market. Of the finger implants in RA patients (n=16), 12 implants failed of which ten were due to rotation. Time to failure ranged from two to 48 months (mean 15 months). The authors do not recommend the use of this implant, especially in cases of rheumatoid arthritis

Introduction. In order to prepare hamstring autograft, suture fixation to the tendon is required to secure and handle the tendon during harvest and preparation. We use a simple, grasping suture which doesn't require suture of the tendon, thus saving time and avoiding violation of the graft itself. We present this technique, with results of mechanical testing compared to a standard whip suture, traditionally used to handle hamstring autograft. Methods and materials. Twelve uniform ovine flexor tendons were prepared. A number two braided polyester suture was used in all cases. Six tendons were prepared with a standard, non-locking whip-suture, maintaining uniformity of suture bite and working length between samples. Six tendons were prepared with the utility suture, also taking care to maintain uniformity. The suture was applied by tying the thread around the tendon with a single-throw granny knot then symmetrically wrapping the suture ends from proximal to distal and securing with another single throw, allowing compression of the tendon with longitudinal tension on the suture. All the samples were tested to failure in uniaxial tension in a materials testing machine. Peak load values and load/displacement curves were acquired and results analysed with a two-sample T-test assuming significance at P<0.05. Results. Modes of failure between the groups, as characterised by the load/displacement curves were quite distinct. Peak load to failure was lower in the utility suture group but all failures occurred when the suture snapped. Thus the peak load to failure of the suture/tendon construct exceeded the breaking strain of the suture material. Conclusion. The grasping utility suture described here is sufficiently strong to harvest and handle hamstring autograft without passing a needle through the graft, saving time and avoiding violation of the graft itself. The lower loads at failure, despite failure occurring due to suture snapping, may reflect differing knot orientation between groups

Aims: The modes of failure of bipolar arthroplasty and outcomes following revision surgery have not been described. Methods: 7 patients (2f, 5m) who previously underwent bipolar arthroplasty were treated with revision surgery. Patient self-assessment was obtained pre- and postoperatively with a satisfaction survey, SF-36, SST, ASES scores, and preoperative/postoperative x-rays. Results: Modes of failure included rotator cuff failure 6/7, superior arch deficiency (4/7) and glenoid erosion (3/7). Revision surgery was performed to reconstruct instability, resurface eroded bone and repair available rotator cuff tissue. Anterior superior arch deficiencies were all revised to a semiconstrained reverse prosthesis. Other patients (3/7) were revised to unconstrained TSA. In this group, additionally soft tissue reconstructions were performed. ASES scores improved from 33 preoperatively to 55.5 postoperatively (P < 0.05). The mean SF 36 domains for PHC improved from 33.9 to 38.4 (P < 0.05). The mean VAS score for pain improved from 5.9 to 2.9 (p< 0.05). Mean active elevation increased from 60° to 78°. External rotation improved from 45° to 60°. 80% reported excellent/good, 20% reported satisfactory and none reported unsatisfactory outcome. Complications included 2 patients with recurrent instability. Conclusion: Revision shoulder arthroplasty following failure of a bipolar prosthesis requires reconstructive options of a semiconstrained prosthesis and conventional TSA with complex soft tissue reconstructions. Soft tissue problems such as superior arch deficiency and rotator cuff tears are the most common mode of failure. Patients may be improved from pain but limited improvement of shoulder function is to be expected

CURRENT INDICATIONS. The ideal patient for unicompartmental arthroplasty has been described as an elderly sedentary individual with significant joint space loss isolated to either the medial or lateral compartment. Angular deformity should be no more than 5 or 10 degrees off a neutral mechanical axis. Ideal weight is below 180 pounds. Pre-operative flexion contracture should be less than 15 degrees. At surgery, the anterior cruciate ligament is ideally intact and there is no evidence of inflammatory synovitis. (Kozinn, Scott, 1989) Indications for the procedure have broadened today because of the availability of less invasive operative techniques and more rapid recovery with UKA. Because of its conservative nature, the procedure is being thought of as a conservative first arthroplasty in the middle-aged patient. Because of its less invasive nature with more rapid recovery and potentially less medical morbidity, it is being considered as the “last arthroplasty” in the octogenarian or older. OUTCOMES OF UKA. Initial results reported for UKA in the 1970s were not as encouraging as they are today. This is most likely due to lessons that had yet to be learned about patient selection, surgical technique and prosthetic design. By the 1980s, reported results were improving with post-operative range of motion much higher than that reported for TKA. As longer follow-ups were reported, results were obtained that were competitive with those reported for TKA. Through the first post-operative decade, revision rates were being seen at approximately 1% failure per year or a 90% survivorship of the prosthesis at 10 years. More recently, however, some 10-year results have been reported that have survivorship well over 95% at 10 years. Modes of failure most often consist of problems with component wear or loosening or due to secondary degeneration of the opposite compartment. This latter complication is usually a late cause of failure, but can occur early if the alignment of the knee is over-corrected by the surgical technique. UKA AS AN OPTION IN THE MIDDLE-AGED PATIENT. Although the classic selection criteria for UKA have emphasised the elderly patient as a candidate, the indications for UKA have been extended to a younger age group. The advantages of UKA in the middle-aged patient (especially female) are its higher initial success, few early complications, preservation of both cruciate ligaments and easier future conversion. Caution should be used, however, in advocating this procedure for the young, heavy, athletic person, as high levels of physical activity may be detrimental to the longevity of the procedure. LATERAL UKA. Lateral UKA is performed much less often than medial UKA (approximately 10% of UKAs are lateral). It is technically more challenging than medial arthroplasty. Some surgeons perform the procedure through a small lateral arthrotomy while others advocate a medial approach with care to avoid injury to the medial meniscus. This medial approach still yields excellent results with a short recovery while allowing the surgeon wide exposure to assess the joint, accurately perform the procedure and intra-operatively convert to a total knee arthroplasty if indicated. THE FUTURE. Research must continue in the areas of ideal patient selection, prosthetic design and surgical technique. Improvements in the durability of the polyethylene will enhance longevity. Mobile bearing articulations may improve long-term polyethylene wear by providing increased surface conformity without constraint

Aims

The primary aim of this study was to determine the ten-year outcome following surgical treatment for femoroacetabular impingement (FAI). We assessed whether the evolution of practice from open to arthroscopic techniques influenced outcomes and tested whether any patient, radiological, or surgical factors were associated with outcome.

Aims

Advances in surgical technique and implant design may influence the incidence and mechanism of failure resulting in revision total hip arthroplasty (rTHA). The purpose of the current study was to characterize aetiologies requiring rTHA, and to determine whether temporal changes existed in these aetiologies over a ten-year period.

Objectives

We aimed to further evaluate the biomechanical characteristics of two locking screws versus three standard bicortical screws in synthetic models of normal and osteoporotic bone.