Aims. Complete ruptures of the ulnar collateral ligament (UCL) of the thumb are a common injury, yet little is known about their current management in the UK. The objective of this study was to assess the way complete UCL ruptures are managed in the UK. Methods. We carried out a multicentre, survey-based cross-sectional study in 37 UK centres over a 16-month period from June 2022 to September 2023. The survey results were analyzed descriptively. Results. A total of 37 centres participated, of which nine were tertiary referral hand centres and 28 were district general hospitals. There was a total of 112 respondents (69 surgeons and 43 hand therapists). The strongest influence on the decision to offer surgery was the lack of a firm ‘endpoint’ to stressing the metacarpophalangeal joint (MCPJ) in either full extension or with the MCPJ in 30° of flexion. There was variability in whether additional imaging was used in managing acute UCL injuries, with 46% routinely using additional imaging while 54% did not. The use of a bone anchor was by far the most common surgical option for reconstructing an acute ligament avulsion (97%, n = 67) with a transosseous suture used by 3% (n = 2). The most common duration of immobilization for those managed conservatively was six weeks (58%, n = 65) and four weeks (30%, n = 34). Most surgeons (87%, n = 60) and hand therapists (95%, n = 41) would consider randomizing patients with complete UCL ruptures in a future clinical trial. Conclusion. The management of complete UCL ruptures in the UK is highly variable in certain areas, and there is a willingness for clinical trials on this subject. Cite this article: Bone Jt Open 2024;5(8):708–714

Aims. The conventionally described mechanism of distal biceps tendon rupture (DBTR) is of a ‘considerable extension force suddenly applied to a resisting, actively flexed forearm’. This has been commonly paraphrased as an ‘eccentric contracture to a flexed elbow’. Both definitions have been frequently used in the literature with little objective analysis or citation. The aim of the present study was to use video footage of real time distal biceps ruptures to revisit and objectively define the mechanism of injury. Methods. An online search identified 61 videos reporting a DBTR. Videos were independently reviewed by three surgeons to assess forearm rotation, elbow flexion, shoulder position, and type of muscle contraction being exerted at the time of rupture. Prospective data on mechanism of injury and arm position was also collected concurrently for 22 consecutive patients diagnosed with an acute DBTR in order to corroborate the video analysis. Results. Four videos were excluded, leaving 57 for final analysis. Mechanisms of injury included deadlift, bicep curls, calisthenics, arm wrestling, heavy lifting, and boxing. In all, 98% of ruptures occurred with the arm in supination and 89% occurred at 0° to 10° of elbow flexion. Regarding muscle activity, 88% occurred during isometric contraction, 7% during eccentric contraction, and 5% during concentric contraction. Interobserver correlation scores were calculated as 0.66 to 0.89 using the free-marginal Fleiss Kappa tool. The prospectively collected patient data was consistent with the video analysis, with 82% of injuries occurring in supination and 95% in relative elbow extension. Conclusion. Contrary to the classically described injury mechanism, in this study the usual arm position during DBTR was forearm supination and elbow extension, and the muscle contraction was typically isometric. This was demonstrated for both video analysis and ‘real’ patients across a range of activities leading to rupture. Cite this article: Bone Jt Open 2022;3(10):826–831

Aims. The aim of this systematic review and meta-analysis was to gather epidemiological information on selected musculoskeletal injuries and to provide pooled injury-specific incidence rates. Methods. PubMed (National Library of Medicine) and Scopus (Elsevier) databases were searched. Articles were eligible for inclusion if they reported incidence rate (or count with population at risk), contained data on adult population, and were written in English language. The number of cases and population at risk were collected, and the pooled incidence rates (per 100,000 person-years) with 95% confidence intervals (CIs) were calculated by using either a fixed or random effects model. Results. The screening of titles yielded 206 articles eligible for inclusion in the study. Of these, 173 (84%) articles provided sufficient information to be included in the pooled incidence rates. Incidences of fractures were investigated in 154 studies, and the most common fractures in the whole adult population based on the pooled incidence rates were distal radius fractures (212.0, 95% CI 178.1 to 252.4 per 100,000 person-years), finger fractures (117.1, 95% CI 105.3 to 130.2 per 100,000 person-years), and hip fractures (112.9, 95% CI 82.2 to 154.9 per 100,000 person-years). The most common sprains and dislocations were ankle sprains (429.4, 95% CI 243.0 to 759.0 per 100,000 person-years) and first-time patellar dislocations (32.8, 95% CI 21.6 to 49.7 per 100,000 person-years). The most common injuries were anterior cruciate ligament (17.5, 95% CI 6.0 to 50.2 per 100,000 person-years) and Achilles (13.7, 95% CI 9.6 to 19.5 per 100,000 person-years) ruptures. Conclusion. The presented pooled incidence estimates serve as important references in assessing the global economic and social burden of musculoskeletal injuries. Cite this article: Bone Joint Res 2022;11(11):814–825

Determine the infection risk of nonoperative versus operative repair of extraperitoneal bladder ruptures in patients with pelvic ring injuries. Pelvic ring injuries with extraperitoneal bladder ruptures were identified from a prospective trauma registry at two level 1 trauma centers from 2014 to 2020. Patients, injuries, treatments, and complications were reviewed. Using Fisher's exact test with significance at P value < 0.05, associations between injury treatment and outcomes were determined. Of the 1127 patients with pelvic ring injuries, 68 (6%) had a concomitant extraperitoneal bladder rupture. All patients received IV antibiotics for an average of 2.5 days. A suprapubic catheter was placed in 4 patients. Bladder repairs were performed in 55 (81%) patients, 28 of those simultaneous with ORIF anterior pelvic ring. The other 27 bladder repair patients underwent initial ex-lap with bladder repair and on average had pelvic fixation 2.2 days later. Nonoperative management of bladder rupture with prolonged Foley catheterization was used in 13 patients. Improved fracture reduction was noted in the ORIF cohort compared to the closed reduction external fixation cohort (P = 0.04). There were 5 (7%) deep infections. Deep infection was associated with nonoperative management of bladder rupture (P = 0.003) and use of a suprapubic catheter (P = 0.02). Not repairing the bladder increased odds of infection 17-fold compared to repair (OR 16.9, 95% CI 1.75 – 164, P = 0.01). Operative repair of extraperitoneal bladder ruptures substantially decreases risk of infection in patients with pelvic ring injuries. ORIF of anterior pelvic ring does not increase risk of infection and results in better reductions compared to closed reduction. Suprapubic catheters should be avoided if possible due to increased infection risk later. Treatment algorithms for pelvic ring injuries with extraperitoneal bladder ruptures should recommend early bladder repair and emphasize anterior pelvic ORIF

Abstract. Objectives. Achilles tendon ruptures are common in the UK, with data demonstrating a significant rise in incidence over the past years. Chronic Achilles ruptures have been less well defined in literature, and repair techniques vary significantly. A surge in publications reporting various management options for chronic Achilles ruptures has necessitated a review that systematically maps and summarises current evidence regarding treatments and identifies areas for future research. This scoping review aims to improve knowledge of various treatment strategies and their associated outcomes, thereby aiding clinicians in optimising treatment protocols. Methods. The Arksey and O'Malley, Levac and Peters frameworks were used. A computer-based search in PubMed, Embase, Emcare, Cinahl, ISI Web of Science and Scopus was performed for articles reporting the treatment of chronic Achilles ruptures. Two reviewers independently performed title/abstract and full text screening according to a pre-defined selection criteria. Results. A total of 747 articles were identified, of which 73 were finally included. Various management strategies were described with flexor hallucis longus tendon transfer being the most common. The American Orthopaedic Foot and Ankle Society (AOFAS) score was the most commonly reported outcome, but 16 other measures were described within the literatures. All studies comparing pre- and post-operative outcomes reported a significant improvement. 50 studies reported complications, with an overall pooled complication rate of 168/1065 (15.8%). Conclusions. Beneficial results were reported following various techniques, but comparison between these was challenging due to the low-level study designs used and confounding factors including treatment delay and tendon gap size. Further research exploring the efficacy of different techniques is required to facilitate the development of evidenced-based treatment protocols. Such a work would allow for clinicians to better understand the suitability of specific techniques, thereby selecting the optimal management strategy for each individual patient

There is currently no commercially available and clinically successful treatment for scapholunate interosseous ligament rupture, the latter leading to the development of hand-wrist osteoarthritis. We have created a novel biodegradable implant which fixed the dissociated scaphoid and lunate bones and encourages regeneration of the ruptured native ligament. To determine if scaphoid and lunate kinematics in cadaveric specimens were maintained during robotic manipulation, when comparing the native wrist with intact ligament and when the implant was installed. Ten cadaveric experiments were performed with identical conditions, except for implant geometry that was personalised to the anatomy of each cadaveric specimen. Each cadaveric arm was mounted upright in a six degrees of freedom robot using k-wires drilled through the radius, ulna, and metacarpals. Infrared markers were attached to scaphoid, lunate, radius, and 3rd metacarpal. Cadaveric specimens were robotically manipulated through flexion-extension and ulnar-radial deviation by ±40° and ±30°, respectively. The cadaveric scaphoid and lunate kinematics were examined with 1) intact native ligament, 2) severed ligament, 3) and installed implant. Digital wrist models were generated from computed tomography scans and included implant geometry, orientation, and location. Motion data were filtered and aligned relative to neutral wrist in the digital models of each specimen using anatomical landmarks. Implant insertion points in the scaphoid and lunate over time were then calculated using digital models, marker data, and inverse kinematics. Root mean squared distance was compared between severed and implant configurations, relative to intact. Preliminary data from five cadaveric specimens indicate that the implant reduced distance between scaphoid and lunate compared to severed configuration for all but three trials. Preliminary results indicate our novel implant reduced scapho-lunate gap caused by ligament transection. Future analysis will reveal if the implant can achieve wrist kinematics similar to the native intact wrist

We reviewed the records of 107 consecutive patients who had undergone surgery for disruption of the knee extensor mechanism to test whether an association existed between rupture of the quadriceps tendon and the presence of a patellar spur. The available standard pre-operative lateral radiographs were examined to see if a patellar spur was an indicator for rupture of the quadriceps tendon in this group of patients. Of the 107 patients, 12 underwent repair of a ruptured patellar tendon, 59 had an open reduction and internal fixation of a patellar fracture and 36 repair of a ruptured quadriceps tendon. In the 88 available lateral radiographs, patellar spurs were present significantly more commonly (p < 0.0005) in patients operated on for rupture of the quadriceps tendon (79%) than in patients with rupture of the patellar tendon (27%) or fracture of the patella (15%). In patients presenting with failure of the extensor mechanism of the knee in the presence of a patellar spur, rupture of the quadriceps tendon should be considered as a possible diagnosis

Introduction. Chronic ruptures of the quadriceps tendon after total knee arthroplasty (TKA) are rare but are a devastating complication. The objective of this study was to validate the use of fresh frozen total fresh quadriceps tendon allografts for quadriceps tendon reconstruction. The hypothesis of this work was that the graft was functional in more than 67% of cases, a higher percentage than the results of conventional treatments. Material – methods. We designed a continuous monocentric retrospective study of all patients operated on between 2009 and 2017 for a chronic rupture of the quadriceps tendon after TKA by quadriceps allograft reconstruction. The usual demographic and perioperative data and the rehabilitation protocols followed were collected. Initial and final radiographs were analyzed to measure patellar height variation. The main criterion was the possibility of achieving an active extension of the knee with a quadriceps contraction force greater than or equal to 3/5 or the possibility of lifting the heel off the ground in a sitting position. Results. 29 patients with 33 allografts were included; 3 iterative allografts were performed on ruptures of the initial transplant and 1 patient was grafted on both sides in one step. There were 21 women and 8 men with a mean age of 73 years, and a mean body mass index of 33 kg/m. 2. Ruptures occurred in 22 cases after chronic periprosthetic infection. Walking was allowed immediately in 29 cases, but free mobilization was delayed in 29 cases. Complications affected 22 cases, but the majority of complications were not related to allograft use (including infectious failures and periprosthetic fractures). After a mean follow-up of 52 months, 28 allografts were still in place, and 22 allografts were considered functional. The active quadriceps extension force was rated on average at 3.5/5. The average pre/post-operative patellar height differential was +2 mm. Discussion. This continuous series of 33 allografts is in line with recent publications on the subject. It confirms their negative impact on the functional outcome of the TKA. The complication rate is high but the specific complication rate is not prohibitive. Two thirds of transplants are functional in the long term. Early rehabilitation procedures can be used in these difficult patients with encouraging results. The management of chronic ruptures of the quadriceps tendon after TKA by quadriceps allograft must be part of the current therapeutic options

The Swansea Morriston Achilles Rupture Treatment (SMART) programme was introduced in 2008. This paper summarises the outcome of this programme. Patients with a rupture of the Achilles tendon treated in our unit follow a comprehensive management protocol that includes a dedicated Achilles clinic, ultrasound examination, the use of functional orthoses, early weight-bearing, an accelerated exercise regime and guidelines for return to work and sport. The choice of conservative or surgical treatment was based on ultrasound findings. . The rate of re-rupture, the outcome using the Achilles Tendon Total Rupture Score (ATRS) and the Achilles Tendon Repair Score, (AS), and the complications were recorded. An elementary cost analysis was also performed. . Between 2008 and 2014 a total of 273 patients presented with an acute rupture 211 of whom were managed conservatively and 62 had surgical repair. There were three re-ruptures (1.1%). There were 215 men and 58 women with a mean age of 46.5 years (20 to 86). Functional outcome was satisfactory. Mean ATRS and AS at four months was 53.0 (. sd . 14), 64.9 (. sd. 15) (n = 135), six months 67.8 (. sd. 16), 73.8 (. sd. 15) (n = 103) and nine months (72.4; . sd. 14) 72.3 (. sd. 13) (n = 43). The programme realised estimated cost savings exceeding £91 000 per annum. The SMART programme resulted in a low rate of re-rupture, a satisfactory outcome, a reduced rate of surgical intervention and a reduction in healthcare costs. Cite this article: Bone Joint J 2015; 97-B:510–15

We hypothesised that a minimally invasive peroneus brevis tendon transfer would be effective for the management of a chronic rupture of the Achilles tendon. In 17 patients (three women, 14 men) who underwent minimally invasive transfer and tenodesis of the peroneus brevis to the calcaneum, at a mean follow-up of 4.6 years (2 to 7) the modified Achilles tendon total rupture score (ATRS) was recorded and the maximum circumference of the calf of the operated and contralateral limbs was measured. The strength of isometric plantar flexion of the gastrocsoleus complex and of eversion of the ankle were measured bilaterally. Functional outcomes were classified according to the four-point Boyden scale. . At the latest review, the mean maximum circumference of the calf of the operated limb was not significantly different from the pre-operative mean value, (41.4 cm, 32 to 50 vs 40.6 cm, 33 to 46; p = 0.45), and not significantly less than that of the contralateral limb (43.1 cm, 35 to 52; p = 0.16). The mean peak torque (244.6 N, 125 to 367) and the strength of eversion of the operated ankle (149.1 N, 65 to 240) were significantly lower (p < 0.01) than those of the contralateral limb (mean peak torque 289, 145 to 419; strength of eversion: 175.2, 71 to 280). The mean ATRS significantly improved from 58 pre-operatively (35 to 68) to 91 (75 to 97; 95% confidence interval 85.3 to 93.2) at the time of final review. Of 13 patients who practised sport at the time of injury, ten still undertook recreational activities. . This procedure may be safely performed, is minimally invasive, and allows most patients to return to pre-injury sport and daily activities. Cite this article: Bone Joint J 2015;97-B:353–7

Aims. The aim of this systematic review and meta-analysis is to evaluate differences in functional outcomes and complications between single- (SI) and double-incision (DI) techniques for the treatment of distal biceps tendon rupture. Methods. A comprehensive search on PubMed, MEDLINE, Scopus, and Cochrane Central databases was conducted to identify studies reporting comparative results of the SI versus the DI approach. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement was used for search strategy. Of 606 titles, 13 studies met the inclusion criteria; methodological quality was assessed with the Newcastle-Ottawa scale. Random- and fixed-effects models were used to find differences in outcomes between the two surgical approaches. The range of motion (ROM) and the Disabilities of the Arm, Shoulder and Hand (DASH) scores, as well as neurological and non-neurological complications, were assessed. Results. A total of 2,622 patients were identified. No significant differences in DASH score were detected between the techniques. The SI approach showed significantly greater ROM in flexion (standardized mean difference (SMD) -0.508; 95% confidence interval (CI) -0.904 to -0.112) and pronation (SMD -0.325, 95% CI -0.637 to -0.012). The DI technique was associated with significantly less risk of lateral antebrachial cutaneous nerve damage (odds ratio (OR) 4.239, 95% CI 2.171 to 8.278), but no differences were found for other nerves evaluated. The SI group showed significantly fewer events of heterotopic ossification (OR 0.430, 95% CI 0.226 to 0.816) and a lower reoperation rate (OR 0.503, 95% CI 0.317 to 0.798). Conclusion. No significant differences in functional scores can be expected between the SI and DI approaches after distal biceps tendon repair. The SI approach showed greater flexion and pronation ROM and a lower risk of heterotopic ossification and reoperation. The DI approach was favourable in terms of lower risk of neurological complications. Cite this article: Bone Joint J 2020;102-B(12):1608–1617

Disruption of the extensor mechanism in total knee arthroplasty may occur by tubercle avulsion, patellar or quadriceps tendon rupture, or patella fracture, and whether occurring intra-operatively or post-operatively can be difficult to manage and is associated with a significant rate of failure and associated complications. This surgery is frequently performed in compromised tissues, and repairs must frequently be protected with cerclage wiring and/or augmentation with local tendon (semi-tendinosis, gracilis) which may also be used to treat soft-tissue loss in the face of chronic disruption. Quadriceps rupture may be treated with conservative therapy if the patient retains active extension. Component loosening or loss of active extension of 20° or greater are clear indications for surgical treatment of patellar fracture. Acute patellar tendon disruption may be treated by primary repair. Chronic extensor failure is often complicated by tissue loss and retraction can be treated with medial gastrocnemius flaps, achilles tendon allografts, and complete extensor mechanism allografts. Attention to fixing the graft in full extension is mandatory to prevent severe extensor lag as the graft stretches out over time

Aims. This prospective cohort study aimed to determine if the size of the tendon gap following acute tendo Achillis rupture influences the functional outcome following non-operative treatment. Patients and methods. All patients presenting with acute unilateral tendo Achillis rupture were considered for the study. Dynamic ultrasound examination was performed to confirm the diagnosis and measure the gap between ruptured tendon ends. Outcome was assessed using dynamometric testing of plantarflexion and the Achilles tendon rupture score (ATRS) six months after the completion of a rehabilitation programme. Results. 38 patients (mean age 52 years, range 29–78 years) completed the study. Patients with a gap ≥10mm with the ankle in the neutral position had significantly greater peak torque deficit than those with gaps < 10mm (mean 23.3% vs 14.3%, P=0.023). However, there was no overall correlation between gap size and torque deficit (τ=0.103), suggesting a non-linear relationship. There was also weak correlation between ATRS and peak torque deficit (τ=−0.305), with no difference in ATRS between the two groups (mean score 87.2 vs 87.4, P=0.467). Conclusion. This is the first study to identify tendon gap size as a predictor of functional outcome in acute tendo Achillis rupture, although the precise relationship between gap size and plantarflexion strength remains unclear. Large, multi-centre studies will be needed to clarify this relationship and identify population subgroups in whom deficits in peak torque are reflected in patient-reported outcome measures

Aims. To validate the Sydney Hamstring Origin Rupture Evaluation (SHORE), a hamstring-specific clinical assessment tool to evaluate patient outcomes following surgical treatment. Methods. A prospective study of 70 unilateral hamstring surgical repairs, with a mean age of 47.3 years (15 to 73). Patients completed the SHORE preoperatively and at six months post-surgery, and then completed both the SHORE and Perth Hamstring Assessment Tool (PHAT) at three years post-surgery. The SHORE questionnaire was validated through the evaluation of its psychometric properties, including; internal consistency, reproducibility, reliability, sensitivity to change, and ceiling effect. Construct validity was assessed using Pearson’s correlation analysis to examine the strength of association between the SHORE and the PHAT. Results. The SHORE demonstrated an excellent completion rate (100%), high internal consistency (Cronbach’s alpha 0.78), and good reproducibility (intraclass correlation coefficient (ICC) 0.82). The SHORE had a high correlation with the validated PHAT score. It was more sensitive in detecting clinical change compared to the PHAT. A ceiling effect was not present in the SHORE at six months; however, a ceiling effect was identified in both scores at three years post-surgery. Conclusion. This study has validated the SHORE patient reported outcome measure (PROM) as a short, practical, reliable, valid, and responsive tool that can be used to assess symptom and function following hamstring injury and surgical repair. Cite this article: Bone Joint J 2020;102-B(3):388–393

One of the factors that influence the outcome after rupture of the tendo Achillis is abnormality of gait. We prospectively assessed 14 patients and 15 normal control subjects using an in-shoe plantar pressure measurement system. There was a significant reduction in peak mean forefoot pressure in the early period of rehabilitation (p < 0.001). There was a concomitant rise in heel pressure on the injured side (p = 0.05). However, there was no difference in cadence, as determined by the duration of the terminal stance and pre-swing phases as a proportion of total stance. The forefoot pressure deficit in the group with tendon ruptures was smaller when assessed six months after the injury but was still significant (p = 0.029). Pedobarographic assessment confirms that there are marked abnormalities within the gait cycle. Rehabilitation programmes which address these abnormalities may improve outcome

Subcutaneous rupture of the tendon of tibialis anterior immediately proximal to its insertion affects patients over the age of 45 years and is most common in the seventh decade. The symptoms at the time of rupture are milder than is the case with rupture of the calcaneal tendon and the early disability is slight. Thus, affected patients commonly present several weeks or months after rupture and at a stage when reattachment of the tendon to its normal site of insertion (the most satisfactory surgical management) is impossible. Although the disability is slight if repair is not performed, there should be no disability after surgical repair and this should be offered to those patients who lead an active life and who present in the first three months after rupture. The relevant literature is reviewed and experience with four further patients is recounted

It has been suggested that an increased posterior tibial slope (PTS) and a narrow notch width index (NWI) increase the risk of anterior cruciate ligament (ACL) injury. The aim of this study was to establish why there are conflicting reports on their significance. A total of fifty patients with a ruptured ACL and 50 patients with an intact ACL were included in the study. The group with ACL rupture had a statistically significantly increased PTS (p < 0.001) and a smaller NWI (p < 0.001) than the control group. When a high PTS and/or a narrow NWI were defined as risk factors for an ACL rupture, 80% of patients had at least one risk factor present; only 24% had both factors present. In both groups the PTS was negatively correlated to the NWI (correlation coefficient = -0.28, p = 0.0052). Using a univariate model, PTS and NWI appear to be correlated to rupture of the ACL. Using a logistic regression model, the PTS (p = 0.006) and the NWI (p < 0.0001) remain significant risk factors. From these results, either a steep PTS or a narrow NWI predisposes an individual to ACL injury. Future studies should consider these factors in combination rather than in isolation

The recent advance of drug therapy for RA tends to replace preventive surgery, for example synovectomy. A rupture of a dorsal extensor tendon of the hand is an absolute indication for surgery, however. Such tendon ruptures are usually treated by tendon reconstruction and synovectomy of wrist joint. At our department, reconstructive surgery was administered with synovectomy for extensor tendon ruptures of the hand in 97 hands for 86 patients until June 2005. Recently, however, we occasionally encounter ruptures of extensor tendons not associated with severe synovitis. To treat such tendon ruptures, we usually administer tendon transfers in combination with tenosynovectomy through a small skin incision. Because this surgical procedure has achieved excellent results, we report our experience. This study included 15 patients who received tenosynovectomy in combination with tendon transfers in 14 hands since February 2001. This surgical procedure is indicated for tendon ruptures associated with mild synovitis (swelling) without instability on the ulnar distal end. As a rule, a 2–3 cm transverse skin incision was made on the dorsum of the hand under maxillary nerve block. After exposure of the distal ruptured end of the tendon, tenosynovectomy was administered through the incision. Then, the distal end was transferred to the adjacent normal tendon and fixed to it with sutures. Postoperatively, the repair was immobilized with bandage. The patient was allowed actively to extend and bend the hand on the next day. As a rule, this operation is administered on an outpatient basis. The postoperative course was uneventful, without rupture of the repair. The preoperative ranges of motion of the MP and PIP joints were retained postoperatively without difficulty in ADL

The recent introduction of intra-articular local anaesthetic techniques following total joint arthroplasty have demonstrated improvements in post-operative pain control, early joint mobilisation and may contribute to early discharge. Following intra-operative infiltration, the CALEDonian Technique requires ropivicaine to be administered postoperatively via an epidural catheter and filter, 20 to 40 ml over 60 seconds, on three occasions. Epidural filter catheters are used to prevent bacterial contamination during injection and have demonstrated 100% efficacy when intact. However, on internal departmental audit we have become aware of a filter membrane rupture rate approximating 10%. We therefore investigated the variables of syringe size and rate of administration in the occurrence of filter ruptures. Using a standard primed epidural catheter set (Perifix B Braun), pressure measurements were taken pre- and post-filter. Recordings using the filter with attached catheter tubing were undertaken using 5 ml, 10 ml and 20 ml syringes (n=10) during infusion of a standard 5 ml volume. Controlled (over 1 min and following departmental protocol) and forced (over less than 15 seconds) infusions were undertaken manually and the experiment also undertaken using an automated syringe driver with 40 ml infused at a rate of 400 ml/hr. Each experiment was repeated ten times. Infusion pressures were measured and filters examined for evidence of rupture. Using departmental protocol, controlled infusions independent of syringe size generated consistently low pressures, averaging 115 kPa, with no filter ruptures. Forced administration, independent of syringe size, generated pressures averaging 625.1 kPa. This is above the filter threshold and resulted in almost universal filter rupture. An automated device infusing at a rate of 400 ml/hr again generated low pressures and no filter ruptures. Our study demonstrates low infusion pressures and no filter ruptures, independent of syringe size, when departmental protocol is adhered to suggesting that a human element may be in-part responsible for filter rupture. Although the technique currently used is safe, our audit has raised awareness of a potential difficulty and has lead to re-education of staff involved in this process. Consideration is being given to the possibility of automating infusions in the future and a process of re-audit of filter rupture will be undertaken

1. Twenty-two cases of synovial rupture of the knee have been studied. This condition may complicate any chronic synovitis of the knee in which a tense intra-articular effusion is subjected to increased tension during flexion and extension of the joint. 2. Two types of rupture have been seen; a herniation of the synovial membrane into the popliteal fossa and down the leg, and an acute synovial tear with extravasation of joint contents between the muscle planes of the calf. 3. The diagnosis of this condition, the differentiation of the types of rupture and their treatment are discussed. 4. The acute rupture usually responds to simple bed-rest; the large synovial herniations often need removal and repair of the posterior capsule