Aims. Joint registries classify all further arthroplasty procedures to a knee with an existing partial arthroplasty as revision surgery, regardless of the actual procedure performed. Relatively minor procedures, including bearing exchanges, are classified in the same way as major operations requiring augments and stems. A new classification system is proposed to acknowledge and describe the detail of these procedures, which has implications for risk, recovery, and health economics. Methods. Classification categories were proposed by a surgical consensus group, then ranked by patients, according to perceived invasiveness and implications for recovery. In round one, 26 revision cases were classified by the consensus group. Results were tested for inter-rater reliability. In round two, four additional cases were added for clarity. Round three repeated the survey one month later, subject to inter- and intrarater reliability testing. In round four, five additional expert partial knee arthroplasty surgeons were asked to classify the 30 cases according to the proposed revision partial knee classification (RPKC) system. Results. Four classes were proposed: PR1, where no bone-implant interfaces are affected; PR2, where surgery does not include conversion to total knee arthroplasty, for example, a second partial arthroplasty to a native compartment; PR3, when a standard primary total knee prosthesis is used; and PR4 when revision components are necessary. Round one resulted in 92% inter-rater agreement (Kendall’s W 0.97; p < 0.005), rising to 93% in round two (Kendall’s W 0.98; p < 0.001). Round three demonstrated 97% agreement (Kendall’s W 0.98; p < 0.001), with high intra-rater reliability (interclass correlation coefficient (ICC) 0.99; 95% confidence interval 0.98 to 0.99). Round four resulted in 80% agreement (Kendall’s W 0.92; p < 0.001). Conclusion. The RPKC system accounts for all procedures which may be appropriate following partial knee arthroplasty. It has been shown to be reliable, repeatable and pragmatic. The implications for patient care and health economics are discussed. Cite this article: Bone Jt Open 2021;2(8):638–645

Aims. There is ambiguity surrounding the degree of scaphoid union required to safely allow mobilization following scaphoid waist fracture. Premature mobilization could lead to refracture, but late mobilization may cause stiffness and delay return to normal function. This study aims to explore the risk of refracture at different stages of scaphoid waist fracture union in three common fracture patterns, using a novel finite element method. Methods. The most common anatomical variant of the scaphoid was modelled from a CT scan of a healthy hand and wrist using 3D Slicer freeware. This model was uploaded into COMSOL Multiphysics software to enable the application of physiological enhancements. Three common waist fracture patterns were produced following the Russe classification. Each fracture had differing stages of healing, ranging from 10% to 90% partial union, with increments of 10% union assessed. A physiological force of 100 N acting on the distal pole was applied, with the risk of refracture assessed using the Von Mises stress. Results. Overall, 90% to 30% fracture unions demonstrated a small, gradual increase in the Von Mises stress of all fracture patterns (16.0 MPa to 240.5 MPa). All fracture patterns showed a greater increase in Von Mises stress from 30% to 10% partial union (680.8 MPa to 6,288.6 MPa). Conclusion. Previous studies have suggested 25%, 50%, and 75% partial union as sufficient for resuming hand and wrist mobilization. This study shows that 30% union is sufficient to return to normal hand and wrist function in all three fracture patterns. Both 50% and 75% union are unnecessary and increase the risk of post-fracture stiffness. This study has also demonstrated the feasibility of finite element analysis (FEA) in scaphoid waist fracture research. FEA is a sustainable method which does not require the use of finite scaphoid cadavers, hence increasing accessibility into future scaphoid waist fracture-related research. Cite this article: Bone Jt Open 2023;4(8):612–620

Aims. In elderly patients with osteoarthritis and protrusio who require arthroplasty, dislocation of the hip is difficult due to migration of the femoral head. Traditionally, neck osteotomy is performed in situ, so this is not always achieved. Therefore, the purpose of this study is to describe a partial resection of the posterior wall in severe protrusio. Methods. This is a descriptive observational study, which describes the surgical technique of the partial resection of the posterior wall during hip arthroplasty in patients with severe acetabular protrusio operated on between January 2007 and February 2017. Results. In all, 49 hip arthroplasties were performed. The average age of patients was 60 years, and idiopathic was the most frequent aetiology of protrusio. All patients were treated with femoral head autograft and no intra- or postoperative complications were reported. No patients required revision surgery. Conclusion. Partial resection of the posterior wall demonstrated to be a safe surgical technique with 100% survival in a follow-up to ten years in total hip arthroplasty due to severe acetabular protrusio. Cite this article: Bone Joint Open 2020;1-7:431–437

Aims. Custom-made partial pelvis replacements (PPRs) are increasingly used in the reconstruction of large acetabular defects and have mainly been designed using a triflange approach, requiring extensive soft-tissue dissection. The monoflange design, where primary intramedullary fixation within the ilium combined with a monoflange for rotational stability, was anticipated to overcome this obstacle. The aim of this study was to evaluate the design with regard to functional outcome, complications, and acetabular reconstruction. Methods. Between 2014 and 2023, 79 patients with a mean follow-up of 33 months (SD 22; 9 to 103) were included. Functional outcome was measured using the Harris Hip Score and EuroQol five-dimension questionnaire (EQ-5D). PPR revisions were defined as an endpoint, and subgroups were analyzed to determine risk factors. Results. Implantation was possible in all cases with a 2D centre of rotation deviation of 10 mm (SD 5.8; 1 to 29). PPR revision was necessary in eight (10%) patients. HHS increased significantly from 33 to 72 postoperatively, with a mean increase of 39 points (p < 0.001). Postoperative EQ-5D score was 0.7 (SD 0.3; -0.3 to 1). Risk factor analysis showed significant revision rates for septic indications (p ≤ 0.001) as well as femoral defect size (p = 0.001). Conclusion. Since large acetabular defects are being treated surgically more often, custom-made PPR should be integrated as an option in treatment algorithms. Monoflange PPR, with primary iliac fixation, offers a viable treatment option for Paprosky III defects with promising functional results, while requiring less soft-tissue exposure and allowing immediate full weightbearing. Cite this article: Bone Jt Open 2024;5(8):688–696

Aims. While medial unicompartmental knee arthroplasty (UKA) is indicated for patients with full-thickness cartilage loss, it is occasionally used to treat those with partial-thickness loss. The aim of this study was to investigate the five-year outcomes in a consecutive series of UKAs used in patients with partial thickness cartilage loss in the medial compartment of the knee. Patients and Methods. Between 2002 and 2014, 94 consecutive UKAs were undertaken in 90 patients with partial thickness cartilage loss and followed up independently for a mean of six years (1 to 13). These patients had partial thickness cartilage loss either on both femur and tibia (13 knees), or on either the femur or the tibia, with full thickness loss on the other surface of the joint (18 and 63 knees respectively). Using propensity score analysis, these patients were matched 1:2 based on age, gender and pre-operative Oxford Knee Score (OKS) with knees with full thickness loss on both the femur and tibia. The functional outcomes, implant survival and incidence of re-operations were assessed at one, two and five years post-operatively. A subgroup of 36 knees in 36 patients with partial thickness cartilage loss, who had pre-operative MRI scans, was assessed to identify whether there were any factors identified on MRI that predicted the outcome. Results. Knees with partial thickness cartilage loss had significantly worse functional outcomes at one, two and five years post-operatively compared with those with full thickness loss. A quarter of knees with partial thickness loss had a fair or poor result and a fifth failed to achieve a clinically significant improvement in OKS from a baseline of four points or more; double that seen in knees with full thickness loss. Whilst there was no difference in implant survival between the groups, the rate of re-operation in knees with partial thickness loss was three times higher. Most of the re-operations (three-quarters), were arthroscopies for persistent pain. Compared with those achieving good or excellent outcomes, patients with partial thickness cartilage loss who achieved fair or poor outcomes were younger and had worse pre-operative functional scores. However, there were no other differences in the baseline demographics. MRI findings of full thickness cartilage loss, subchondral oedema, synovitis or effusion did not provide additional prognostic information. Conclusion. Medial UKA should be reserved for patients with full thickness cartilage loss on both the femur and tibia. Whilst some patients with partial thickness loss achieve a good result we cannot currently identify which these will be and in this situation MRI is unhelpful and misleading. Cite this article: Bone Joint J 2017;99-B:475–82

We treated surgically 16 shoulders with an isolated traumatic rupture of the subscapularis tendon over a six-year period. Nine patients had a total and seven a partial tear of the subscapularis tendon. Repair was undertaken through a small deltopectoral groove approach. The mean Constant score improved in total tears from 38.7 to 89.3 points (p = 0.003) and in partial tears from 50.7 to 87.9 points (p = 0.008). The total tears were significantly more improved by surgery than the partial tears (p = 0.001). The delay between trauma and surgery was inversely proportional to the improvement in the Constant score suggesting that early diagnosis and surgical repair improves outcome

The common recommended treatment for infected total hip replacement is two-staged exchange including removal of all components. However, removal of well-fixed femoral stems can result in structural bone damage. We recently reported on an alternative treatment of partial two-stage exchange used in selected cases, in which a well-fixed femoral stem was left and only the acetabular component removed, the joint space was debrided thoroughly, an antibiotic-laden polymethylmethacrylate spacer was moulded using a bulb-type syringe and placed in the acetabulum, intravenous antibiotics were administered during the interval, and delayed re-implantation was performed. In 19 patients treated with this technique from January 2000 to January 2011, 89% were free of infection at a mean follow-up of four years (2 to 11). Since then, disposable silicone moulds have become available to fabricate spacers in separate femoral and head units. The head spacer mould, which incorporates various neck taper adapter options, greatly facilitates the technique of partial two-stage exchange. We report our early experience using disposable silicone head spacer moulds for partial two-stage exchange in seven patients with infected primary hip replacements. Cite this article: Bone Joint J 2014;96-B(11 Suppl A):66–9

We studied the effect of full and partial weight-bearing on venous peak velocity in the legs of 73 subjects. We used colourflow Duplex ultrasound to determine the minimal amount of weight-bearing required to produce the same venous peak velocity as full weight-bearing. We found that the venous peak velocity remains the same in the femoral vein during partial weight-bearing (196 N and above). This is important for postoperative physiotherapy and thrombo-prophylaxis. The median peak velocity was 30 cm/s. This corresponds to an amplification factor of four in relation to the individual resting level (peak velocity). In addition, we found that partial weight-bearing at 196 N can reliably be reproduced. The median value of partial weight-bearing after a three-day training programme was 206 N

Aims. There has been a recent resurgence in interest in combined partial knee arthroplasty (PKA) as an alternative to total knee arthroplasty (TKA). The varied terminology used to describe these procedures leads to confusion and ambiguity in communication between surgeons, allied health professionals, and patients. A standardized classification system is required for patient safety, accurate clinical record-keeping, clear communication, correct coding for appropriate remuneration, and joint registry data collection. Materials and Methods. An advanced PubMed search was conducted, using medical subject headings (MeSH) to identify terms and abbreviations used to describe knee arthroplasty procedures. The search related to TKA, unicompartmental (UKA), patellofemoral (PFA), and combined PKA procedures. Surveys were conducted of orthopaedic surgeons, trainees, and biomechanical engineers, who were asked which of the descriptive terms and abbreviations identified from the literature search they found most intuitive and appropriate to describe each procedure. The results were used to determine a popular consensus. Results. Survey participants preferred “bi-unicondylar arthroplasty” (Bi-UKA) to describe ipsilateral medial and lateral unicompartmental arthroplasty; “medial bi-compartmental arthroplasty” (BCA-M) to describe ipsilateral medial unicompartmental arthroplasty with patellofemoral arthroplasty; “lateral bi-compartmental arthroplasty” (BCA-L) to describe ipsilateral lateral unicompartmental arthroplasty with patellofemoral arthroplasty; and tri-compartmental arthroplasty (TCA) to describe ipsilateral patellofemoral and medial and lateral unicompartmental arthroplasties. “Combined partial knee arthroplasty” (CPKA) was the favoured umbrella term. Conclusion. We recommend bi-unicondylar arthroplasty (Bi-UKA), medial bicompartmental arthroplasty (BCA-M), lateral bicompartmental arthroplasty (BCA-L), and tricompartmental arthroplasty (TCA) as the preferred terms to classify CPKA procedures. Cite this article: Bone Joint J 2019;101-B:922–928

Ten patients are reported who had sustained a partial rupture of the anterior cruciate ligament in a twisting injury of the knee. Nine of the 10 patients presented with a small effusion and pseudo-locking of the knee which was thought to be due to muscular spasm to prevent further ligamentous injury. The patients were examined clinically, under anaesthesia and by arthroscopy and the signs were found to be remarkably similar to those in patients with a tear of the medial meniscus. The mechanism of injury leading to partial rupture of the anterior cruciate ligament is discussed

A study was undertaken to determine whether a significantly different clinical outcome could be expected following nonoperative treatment of acute partial anterior cruciate ligament (ACL) tears from that of complete tears. A detailed follow-up of 107 patients with arthroscopically confirmed tears was obtained; 72 were complete tears and 35 partial. The overall results in those with partial tears were 23% excellent, 29% good, 17% fair, and 31% poor; with complete tears the results were 11% excellent, 20% good, 15% fair, and 54% poor. The patients with partial tears had a lower incidence of associated meniscal tears, needed fewer reconstructions and more of them returned to sport than those with complete tears

In a prospective seven-year study, we treated 32 patients with partial ruptures of the anterior cruciate ligament (ACL) verified by arthroscopy. Twelve knees (38%) progressed to complete ACL deficiency with positive pivot shift tests and increased anteroposterior translation on tests with the KT-1000 arthrometer. Patients with partial ACL tears frequently had limitation for strenuous sports, while those developing ACL deficiency had additional functional limitations involving recreational activities. Three factors were statistically significant in predicting which partial tears would develop complete ACL deficiency: the amount of ligament tearing--one-fourth tears infrequently progressed, one-half tears progressed in 50% and three-fourth tears in 86%; a subtle increase in initial anterior translation; and the occurrence of a subsequent re-injury with giving-way

Although good to excellent short-term results of arthroscopic partial limbectomy of the hip have been reported, there is little information on the long-term outcome of the procedure. We report a case with a 16-year follow-up. A 34-year old woman presented with a three-month history of severe pain and limitation of movement of the hip. Plain radiographs and arthrography showed no abnormality. MRI showed an effusion and a deformity of the anterosuperior part of the labrum. This was confirmed as an inverted labral tear that was debrided arthroscopically. At 16 years post-operatively, she remained symptom-free. Plain radiographs showed no abnormality and MRI suggested that the sealing effect of the scar tissue prevented articular damage and degeneration

The use of a composite osteochondral device for simulating partial hemiarthroplasty was examined. The device was composed of a polyvinyl alcohol hydrogel and a titanium fibre mesh, acting as artificial cartilage and as porous artificial bone, respectively. The titanium fibre mesh was designed to act as an interface material, allowing firm attachment to both the polyvinyl alcohol gel (through injection moulding) and the femoral joint surface (through bony ingrowth). We implanted 22 of these devices into canine femoral heads. Histological findings from the acetabular cartilage and synovial membrane, as well as the attachment of the prosthesis to bone, were examined up until one year after operation. No marked pathological changes were found and firm attachment of the device to the underlying bone was confirmed. The main potential application for this device is for partial surface replacement of the femoral head after osteonecrosis. Other applications could include articular resurfacing and the replacement of intervertebral discs

A retrospective study of 260 industrial amputees was undertaken to determine the long-term functional results of partial foot amputations following trauma. Follow-up ranged from 1 to 68 years with a mean of 16 years. Of 113 partial foot amputees (118 amputations) who had retained their original amputation, the functional end-results were 43% good, 38% fair and 19% poor. Lisfranc and Chopart amputations were better than those at transmetatarsal or digital levels. Of 260 initial amputations 49 (19%) were revised to a Syme's or a below-knee amputation

Aims

To perform an incremental cost-utility analysis and assess the impact of differential costs and case volume on the cost-effectiveness of robotic arm-assisted unicompartmental knee arthroplasty (rUKA) compared to manual (mUKA).

Aims

The aim of this study was to perform an incremental cost-utility analysis and assess the impact of differential costs and case volume on the cost-effectiveness of robotic arm-assisted medial unicompartmental knee arthroplasty (rUKA) compared to manual (mUKA).

Seventy-eight patients who had been operated on for bony entrapment of lumbar nerve roots were studied in an attempt to define the clinical syndrome, and to assess the results of a new technique of decompression which preserves spinal stability. The mean age of the patients was 45 years and 28 of them had previously undergone spinal operations. Pain in the leg was the predominant symptom, with evidence of motor involvement in half of the patients. Signs of nerve root tension were found in only one-third of the patients. The principal factor in the aetiology was degenerative change in the posterior facet joints. Decompression was achieved by a partial undercutting facetectomy. Fifty-nine per cent of the patients obtained a "good" result and 85 per cent were satisfied with the result of their operation. Successful partial facetectomy for bony entrapment of lumbar nerve roots produced rapid and lasting relief of pain

Total removal of the third thoracic vertebra and partial removal of the second and fourth vertebrae together with partial lung resection were successfully performed in a twenty-two-year-old woman with a large, radioresistant, giant-cell tumour which completely surrounded the spinal cord and extended over the left lung. On admission, the patient was in her third episode of paraplegia, the two previous episodes having been temporarily relieved after decompression of the spinal cord by laminectomy and partial removal of the tumour. Three and a half months after operation she was discharged walking without support and with normal sphincter control. Two years later she is free of symptoms and the neurological status is practically normal. Clinical and radiological examinations show no signs of recurrence of the tumour

It is suggested that the operation of partial costectomy is so beneficial psychologically to some young scoliotic patients that it is worth the very small physiological cost demonstrated here in patients who found their "hump" sufficiently embarrassing to curtail their normal social life