We reviewed 87 patients who underwent revision anterior cruciate ligament (ACL) reconstruction. The incidence of meniscal tears and degenerative change was assessed and related to the timing from primary ACL graft failure to revision ACL reconstruction. Patients were divided into either an early group (revision surgery within 6 months of graft failure) or a delayed group. Degenerative change was scored using the French Society of Arthroscopy system. There was a significantly higher incidence of articular cartilage degeneration in the delayed group compared to the early group (53.2% vs 24%, p < 0.01, Mann- Whitney U test). No patients in the early group had advanced degenerative change (SFA grades 3 or 4), compared with 12.9% of patients in the delayed group. There was no significant difference in the incidence of meniscal tears between the two groups. In conclusion, the findings of the study support the view that patients with a failed ACL reconstruction and symptomatic instability should have an early revision reconstruction procedure carried out to minimise the risk of articular degenerative change

Anterior cruciate ligament (ACL) of four major knee ligaments is most crucial ligament to maintain normal knee kinematics. It is well know that ACL dysfunction causes secondary osteoarthritis of the knee. The influence of age on the biomechanical properties of the ACL was examined. The structural properties of 27 pairs of human cadaver knees without OA were evaluated. Specimens were equally divided into three groups of nine pairs each based on age: younger (22 to 35 years), middle (40 to 50 years), and older (60 to 97 years). Tensile tests of the femur-ACL-tibia complex were performed at 30 degrees of knee flexion with the ACL aligned vertically along the direction of applied tensile load. Structural properties of the femur-ACL-tibia complex, as represented by the linear stiffness, ultimate load, and energy absorbed, were found to decrease significantly with specimen age.

On the other hand, little has been written about the arthritic ACL. This study was designed to evaluate the relationship among ROM, cross sections of the intercondylar notch and the macroscopic condition of ACL degeneration. Fifty osteoarthritic patients who underwent TKA as a result of severe osteoarthritis were randomly selected. Occupation rate of the osteophytes to the notch width were measured at the anterior 1/3, middle 1/3, and posterior 1/3 notche images obtained from preoperative tunnel view. ROM was measured preoperatively and under anesthesia. Macroscopic conditions of the ACL and PCL were classified into four types of Normal, Frayed, Partial rupture, and Absent.

The macroscopic ACL conditions were Normal: 12 cases, Frayed: 15 cases, Partial rupture: 14 cases, and Absent: 9 cases. The macroscopic PCL conditions were Normal: 34 cases, Frayed: 9 cases, Partial rupture: 7 cases, and Absent: 0 case. Occupation rate of the osteophytes to the notch correlated to the preoperative varus deformity (p < 0.05). In terms of ACL, the occupation rate of the osteophytes to the notch were 22.9%, 28.8%, 46.0%, and 81.8% in Normal, Frayed, partial ruptured, and Absent, respectively. The patients with more than 40% occupation rate and less than 110 degree of knee flexion angle showed either partial rupture or absent of the ACL during the surgery. Those results correlated with the degree of OA deterioration. We conclude that occupation rate of the osteophytes to the notch poor preoperative ROM is a good predictor of evaluating the ACL degeneration in osteoarthritic knee. We also conclude that ACL dysfunction due to joint space narrowing accelerates the advancement of the knee OA.

In the unstable patellofemoral joint (PFJ), the patella will articulate in an abnormal manner, producing an uneven distribution of forces. It is hypothesised that incongruency of the PFJ, even without clinical instability, may lead to degenerative changes. The aim of this study was to record the change in joint contact area of the PFJ after stabilisation surgery using an established and validated MRI mapping technique. A prospective MRI imaging study of patients with a history of PFJ instability was performed. The patellofemoral joints were imaged with the use of an MRI scan during active movement from 0° through to 40° of flexion. The congruency through measurement of the contact surface area was mapped in 5-mm intervals on axial slices. Post-stabilisation surgery contact area was compared to the pre-surgery contact area. In all, 26 patients were studied. The cohort included 12 male and 14 female patients with a mean age of 26 (15–43). The greatest mean differences in congruency between pre- and post-stabilised PFJs were observed at 0–10 degrees of flexion (0.54 cm. 2. versus 1.18 cm. 2. , p = 0.04) and between 11° and 20° flexion (1.80 cm. 2. versus 3.45 cm. 2. ; p = 0.01). PFJ stabilisation procedures increase joint congruency. If a single axial series is to be obtained on MRI scan to compare the pre- and post-surgery joint congruity, the authors recommend 11° to 20° of tibiofemoral flexion as this was shown to have the greatest difference in contact surface area between pre- and post-operative congruency

There is no agreement as to the superiority or specific indications for cast treatment, percutaneous pinning or open fracture fixation for Bennett's fractures of the thumb metacarpal. We undertook this study to compare the outcomes of treatment for patients treated for Bennett's fracture in the medium term. We reviewed 33 patients treated in our unit for a bennett's fracture to the thumb metacarpal with closed reduction and casting. Each patient was matched with a patient treated surgically. Patients were matched for sex, age, Gedda grade of injury and hand dominance. Patients were reviewed at a minimum of 5-years and 66-patients were reviewed in total. Patients were examined clinically and also asked to complete a DASH questionnaire score and the brief Michigan hand questionnaire. Follow up plain radiographs were taken of the thumb and these were reviewed and graded for degenerative change using the Eaton-Littler score. Sixty-six patients were included in the study, with 33 in the surgical and non-surgical cohorts respectively. The average age was 39 years old. In each cohort, 12/33 were female, 19/33 were right-handed with 25% of individuals injuring their dominant hand. In each coort there were 16 Grade 1 fractures, 4 Grade 2 and 13 Grade 3 fractures. There was no difference between the surgically treated and cast-treatment cohorts of patients when radiographic arthritis, pinch grip, the brief Michigan Hand Questionnaire and pain were assessed at final review. The surgical cohort had significantly lower DASH scores at final follow-up. There was no significant difference in the normalised bMHQ scores. Our study was unable to demonstrate superiority of either operative or non-operative fracture stabilization. Patients in the surgical cohort reported superior satisfaction and DASH scores but did not demonstrate any superiority in any other objectively measured domain

Objectives. Unicompartmental knee replacement (UKR) is a conservative option for degenerative disease, with mobile (Oxford UKR) and fixed bearing (Physica ZUK) the most commonly used devices. The primary reasons for revising UKRs include disease progression (36.9%), loosening (31.7%), and pain (7.5%). Loosening typically occurs due to osteolysis caused by wear particles from the polyethylene (PE) inserts. There is limited published literature which has quantified volumetric material loss from the PE inserts of cemented fixed-bearing UKRs. This study aimed to quantify bearing wear and backside deformation of these PE components. Design and Methods. At our national retrieval centre, we measured changes volumetric bearing wear and backside deformation of 31 explanted fixed-bearing Physica ZUK UKR PE inserts using a peer-reviewed methodology based on coordinate measuring machine analysis. These explants had been revised for any indication [Females (19) and Males (12)]. The location of the wear scars was identified and mapped. We compared the volumetric wear from the bearing surface with contemporary total knee replacement (TKR) inserts. Results. The median (IQR) total volumetric wear of the UKR PEs [96(50-152) mm. 3. ] was significantly higher (p<0.001) than contemporary TKR PEs [40 (24-83) mm. 3. ]. The median (IQR) total volumetric wear of the PEs in males [148(122-200) mm. 3. ] was significantly higher(p=0.016) than in females [56(61-119) mm. 3. ]. The wear scars were situated in the anterior third in 61% of cases, with 26% located posteriorly. Examination of the PE backside surfaces exhibited damage in the area directly inferior to the bearing surface wear scar in the majority of cases. Conclusion. In conclusion, this study highlights significant PE wear of Physica ZUK UKR inserts, with higher wear rates compared to contemporary TKR inserts, particularly in males

Low back pain is the single most common cause for disability in individuals aged 45 years or younger, it carries tremendous weight in socioeconomic considerations. Degenerative aging of the structural components of the spine can be associated with genetic aspects, lifetime of tissue exposure to mechanical stress & loads and environmental factors. Mechanical consequences of the disc degenerative include loss of disc height, segment instability and increase the load on facets joints. All these can lead to degenerative changes and osteophytes that can narrow the spinal canal. Surgery is indicated in patients with spinal stenosis who have intractable pain, altered quality of life, substantially diminished functional capacity, failed non-surgical treatment and are not candidates for non-surgical treatment. The aim was to determine the reasons for refusal of surgery in patients with established degenerative lumber spine pathology eligible for surgery. All patients meeting the study criteria, patients older than 18 years, patients with both clinical and radiological established symptomatic degenerative lumbar spine pathology and patients eligible for surgery but refusing it were recruited. Questionnaire used to investigate reasons why they are refusing surgery. Results 59 were recruited, fifty-one (86.4 %) females and eight (13.6 %) males. Twenty (33.8 %) were between the age of 51 and 60 years, followed by nineteen (32.2 %) between 61 and 70 years, and fourteen (23.7 %) between 71 and 80 years. 43 (72 %) patients had lumber spondylosis complicated by lumber spine stenosis, followed by nine (15.2 %) with lumbar spine spondylolisthesis and four (6.7 %) had adjacent level disease. 28 (47.4 %) were scared of surgery, fifteen (25.4 %) claimed that they are too old for surgery and nine (15.2 %) were not ready. Findings from this study outlined that patients lack information about the spinal surgery. Patients education about spine surgery is needed

Meniscal tears are the most common knee injuries, occurring in acute ruptures or in chronic degenerative conditions. Meniscectomy and meniscal repair are two surgical treatment options. Meniscectomy is easier, faster, and the patient can return to their normal activities earlier. However, this procedure has long-term consequences in the development of degenerative changes in the knee, potentially leading to knee replacement. On the other hand, meniscal repair can offer prolonged benefits to the patients, but it is difficult to perform and requires longer rehabilitation. Sutures are used for meniscal repairs, but they have limitations. They induce tissue damage when passing through the meniscus. Furthermore, under dynamic loading of the knee, they can cause tissue shearing and potentially lead to meniscal repair failure. Our team has developed a new technology of resistant adhesive hydrogels to coat the suture used to repair meniscal tissue. The objective of this study is to biomechanically compare two suture types on bovine menisci specimens: 1) pristine sutures and 2) gel adhesive puncture sealing (GAPS) sutures, on a repaired radial tear under cyclic tensile testing. Five bovine knees were dissected to retrieve the menisci. On the 10 menisci, a complete radial tear was performed. They were separated in two groups and repaired using either pristine (2-0 Vicryl) or GAPS (2-0 Vicryl coated with adhesive hydrogels) with a single stitch and five knots. The repaired menisci were clamped on an Instron machine. The specimens were cyclically preconditioned between one and 10 newtons for 10 cycles and then cyclically loaded for 500 cycles between five and 25 newtons at a frequency of 0.16 Hz. The gap formed between the edges of the tear after 500 cycles was then measured using an electronic measurement device. The suture loop before and after testing was also measured to ensure that there was no suture elongation or loosening of the knot. The groups were compared statistically using Mann-Whitney tests for nonparametric data. The level of significance was set to 0.05. The mean gap formation of the pristine sutures was 5.61 mm (SD = 2.097) after 500 cycles of tensile testing and 2.38 mm (SD = 0.176) for the GAPS sutures. Comparing both groups, the gap formed with the coated sutures was significantly smaller (p = 0.009) than with pristine sutures. The length of the loop was equal before and after loading. Further investigation of tissue damage indicated that the gap was formed by suture filament cutting into the meniscal tissue. The long-term objective of this research is to design a meniscal repair toolbox from which the surgeon can adapt his procedure for each meniscal tear. This preliminary experimentation on bovine menisci is promising because the new GAPS sutures seem to keep the edges of the meniscal tear together better than pristine sutures, with hopes of a clinical correlation with enhanced meniscal healing

Meniscal tears are the most common knee injuries, occurring in acute ruptures or in chronic degenerative conditions. Meniscectomy and meniscal repair are two surgical treatment options. Meniscectomy is easier, faster, and the patient can return to their normal activities earlier. However, this procedure has long-term consequences in the development of degenerative changes in the knee, potentially leading to knee replacement. On the other hand, meniscal repair can offer prolonged benefits to the patients, but it is difficult to perform and requires longer rehabilitation. Sutures are used for meniscal repairs, but they have limitations. They induce tissue damage when passing through the meniscus. Furthermore, under dynamic loading of the knee, they can cause tissue shearing and potentially lead to meniscal repair failure. Our team has developed a new technology of resistant adhesive hydrogels to coat the suture used to repair meniscal tissue. The objective of this study is to biomechanically compare two suture types on bovine menisci specimens: 1) pristine sutures and 2) gel adhesive puncture sealing (GAPS) sutures, on a repaired radial tear under cyclic tensile testing. Five bovine knees were dissected to retrieve the menisci. On the 10 menisci, a complete radial tear was performed. They were separated in two groups and repaired using either pristine (2-0 Vicryl) or GAPS (2-0 Vicryl coated with adhesive hydrogels) with a single stitch and five knots. The repaired menisci were clamped on an Instron machine. The specimens were cyclically preconditioned between one and 10 newtons for 10 cycles and then cyclically loaded for 500 cycles between five and 25 newtons at a frequency of 0.16 Hz. The gap formed between the edges of the tear after 500 cycles was then measured using an electronic measurement device. The suture loop before and after testing was also measured to ensure that there was no suture elongation or loosening of the knot. The groups were compared statistically using Mann-Whitney tests for nonparametric data. The level of significance was set to 0.05. The mean gap formation of the pristine sutures was 5.61 mm (SD = 2.097) after 500 cycles of tensile testing and 2.38 mm (SD = 0.176) for the GAPS sutures. Comparing both groups, the gap formed with the coated sutures was significantly smaller (p = 0.009) than with pristine sutures. The length of the loop was equal before and after loading. Further investigation of tissue damage indicated that the gap was formed by suture filament cutting into the meniscal tissue. The long-term objective of this research is to design a meniscal repair toolbox from which the surgeon can adapt his procedure for each meniscal tear. This preliminary experimentation on bovine menisci is promising because the new GAPS sutures seem to keep the edges of the meniscal tear together better than pristine sutures, with hopes of a clinical correlation with enhanced meniscal healing

Introduction. Distal femoral and proximal tibial osteotomies are effective procedures to treat degenerative disease of the knee joint. Previously described techniques advocate the use of bone graft to promote healing at the osteotomy site. In this present study a novel technique which utilises the osteogenic potential of the cambial periosteal layer to promote healing “from the outside in” is described. Materials and Methods. A retrospective analysis of a consecutive single-surgeon series of 23 open wedge osteotomies around the knee was performed. The median age of the patients was 37 years (range 17–51 years). The aetiology of the deformities included primary genu valgum (8/23), fracture malunion (4/23), multiple epiphyseal dysplasia (4/23), genu varum (2/23), hypophosphataemic rickets (1/23), primary osteoarthritis (1/23), inflammatory arthropathy (1/23), post-polio syndrome (1/23), and pseudoachondroplasia (1/23). Results. There were two cases lost to follow-up with a median follow-up period 17 months (range 1–32 months). Union was achieved in all cases, with 1/23 requiring revision for early fixation failure for technical reasons. The median time to radiographic union 3.2 months (95% Confidence Interval (CI) 2.5–3.8 95% CI). CT scans demonstrated early periosteal callus, beneath the osteoperiosteal flap, bridging the opening wedge cortex. Clinical union occurred at 4.1 months (95% CI 3.9–4.2 months). Complications included superficial surgical site infection (1/23), deep vein thrombosis (1/23), and symptomatic metalwork requiring removal (7/23). Conclusions. The osteoperiosteal flap technique was a safe and effective technique for opening wedge osteotomies around the knee with a reliable rate of union

No animal model currently exists for hip abductor tendon tears. We aimed to 1. Develop a large animal model of delayed abductor tendon repair and 2. To compare the results of acute and delayed tendon repair using this model. Fourteen adult Romney ewes underwent detachment of gluteus medius tendon using diathermy. The detached tendons were protected using silicone tubing. Relook was performed at six and 16 weeks following detachment, histological analysis of the muscle and tendon were performed. We then attempted repair of the tendon in six animals in the six weeks group and compared the results to four acute repairs (tendon detachment and repair performed at the same time). At 12 weeks, all animals were culled and the tendon–bone block taken for histological and mechanical analysis. Histology grading using the modified Movin score confirmed similar tendon degenerative changes at both six and 16 weeks following detachment. Biomechanical testing demonstrated inferior mechanical properties in both the 6 and 16 weeks groups compared to healthy controls. At 12 weeks post repair, the acute repair group had a lower Movin's score (6.9 vs 9.4, p=0.064), and better muscle coverage (79.4% of normal vs 59.8%). On mechanical testing, the acute group had a significantly improved Young's Modulus compared to the delayed repair model (57.5MPa vs 39.4MPa, p=0.032). A six week delay between detachment and repair is sufficient to produce significant degenerative changes in the gluteus medius tendon. There are significant histological and mechanical differences in the acute and delayed repair groups at 12 weeks post op, suggesting that a delayed repair model should be used to study the clinical problem

Aims. The aetiologies of common degenerative spine, hip, and knee pathologies are still not completely understood. Mechanical theories have suggested that those diseases are related to sagittal pelvic morphology and spinopelvic-femoral dynamics. The link between the most widely used parameter for sagittal pelvic morphology, pelvic incidence (PI), and the onset of degenerative lumbar, hip, and knee pathologies has not been studied in a large-scale setting. Methods. A total of 421 patients from the Cohort Hip and Cohort Knee (CHECK) database, a population-based observational cohort, with hip and knee complaints < 6 months, aged between 45 and 65 years old, and with lateral lumbar, hip, and knee radiographs available, were included. Sagittal spinopelvic parameters and pathologies (spondylolisthesis and degenerative disc disease (DDD)) were measured at eight-year follow-up and characteristics of hip and knee osteoarthritis (OA) at baseline and eight-year follow-up. Epidemiology of the degenerative disorders and clinical outcome scores (hip and knee pain and Western Ontario and McMaster Universities Osteoarthritis Index) were compared between low PI (< 50°), normal PI (50° to 60°), and high PI (> 60°) using generalized estimating equations. Results. Demographic details were not different between the different PI groups. L4 to L5 and L5 to S1 spondylolisthesis were more frequently present in subjects with high PI compared to low PI (L4 to L5, OR 3.717; p = 0.024 vs L5 to S1 OR 7.751; p = 0.001). L5 to S1 DDD occurred more in patients with low PI compared to high PI (OR 1.889; p = 0.010), whereas there were no differences in L4 to L5 DDD among individuals with a different PI. The incidence of hip OA was higher in participants with low PI compared to normal (OR 1.262; p = 0.414) or high PI (OR 1.337; p = 0.274), but not statistically different. The incidence of knee OA was higher in individuals with a high PI compared to low PI (OR 1.620; p = 0.034). Conclusion. High PI is a risk factor for development of spondylolisthesis and knee OA. Low pelvic incidence is related to DDD, and may be linked to OA of the hip. Level of Evidence: 1b. Cite this article: Bone Joint J 2020;102-B(9):1261–1267

Tendinopathy is one of the most common orthopaedic pathological conditions characterized by tendon degenerative changes. Excessive mechanical loading is considered as a major causative factor in the development of tendinopathy, but the mechanisms of pathogenesis remain unclear. High mobility group box-1 (HMGB1), a potent inflammatory mediator when released into the matrix, has been identified in the early stage tendinopathy patients. Since the release and contribution of HMGB1 in tendinopathy development due to mechanical overloading is unknown, we investigated the role of HMGB1 in tendinopathy using a mouse intensive treadmill running (ITR) model and injection of glycyrrhizin (GL), a specific inhibitor of HMGB1. A total of 48 mice were divided into four groups, Cage Control group: The animals were allowed to move freely in their cage, GL group: The animals were received daily IP injection of GL (50 mg/kg body weight) for 24 weeks, ITR group: The animals ran on treadmill at 15 meters/min for three h/ day, five days a week for 12 or 24 weeks, GL+ITR group: The animals ran the same protocol as that of ITR group plus daily IP injection of GL for 12 or 24 weeks. Six mice/group were sacrificed at 12 or 24 weeks and the Achilles and patellar tendon tissues were harvested and used for histochemical staining and immunostaining. Mechanical overloading induced HMGB1 released from the cell nuclei to the matrix (Fig. 1a, b) caused tendon inflammation (Fig. 1c, d) and led to tendon degenerative changes (Fig. 1e-j). After 12 weeks of ITR, the tendon tissue near the bone insertion site showed typical tendinopathic changes in cell shape, accumulation of glycosaminoglycans (GAG) (Fig. 1e, f), and increase in SOX-9 staining (Fig. 1g-j). After 24 weeks ITR, the distal site of Achilles tendon showed considerable changes in cell shape (Fig. 2A, g, arrows), which is round compared to more elongated in the control and GL groups (Fig. 2A, e, f). However, daily treatment with GL prior to ITR blocked the cell shape change (Fig. 2A, h) and, ITR induced extensive GAG accumulation in ITR group (Fig. 2B, bottom panel). Furthermore, GL inhibited ITR-induced expression of chondrogenic markers (SOX-9 and collagen II) in the tendons (Fig. 3). Our results showed that mechanical overloading-induced HMGB1 plays a critical role in the development of tendinopathy by initiating tendon inflammation and eventual degeneration characterized by the presence of chondrocyte-like cells, accumulation of proteoglycans, high levels of collagen type II production, and chondrogenic marker SOX-9 expression. These results provide the first evidence for the role of HMGB1 as a therapeutic target to prevent tendinopathy before its onset and block further development at its early inflammation stages. The inhibition of tendinopathy development by GL administration in this study also suggests the putative therapeutic potential of this natural triterpene that is already in clinical use to treat other inflammation-related diseases. For any figures or tables, please contact authors directly

Osteoarthritis (OA) is one of the most prevalent joint diseases involving progressive and degenerative changes to cartilage resulting from a variety of etiologies including post-traumatic incident or aging. OA lesions can be treated at its early stages through cell-based tissue engineering therapies using Mesenchymal Stem Cells (MSCs). In vivo models for evaluating these strategies, have described both chondral (impaction) and osteochondral (biopsy punch) defects. The aim of the investigation was to develop a compact and reproducible defect inducing post-traumatic degenerative changes mimicking early OA. Additionally, a pilot study to evaluate the efficacy of MSC-hydrogel treatment was also assessed. Surgery was performed on New Zealand white rabbits (male, 5–8 months old) with defects created on medial femoral condyle. For developing an appropriate defect, three approaches were used for evaluation: a biopsy punch (n = three at six and twelve weeks), an impaction device1 (n = three at six and twelve weeks) and a dental drill model (n = six at six and twelve weeks). At stated time points, condyles were harvested and decalcified in 10% EDTA, then embedded in Tissue-Tek and sectioned using a cryostat. Upon identification of region of interest, sections were stained with Safranin-O/Fast green and scored using OARSI scoring system by two blinded observers2. For the pilot study, autologous bone marrow was harvested from rabbits and used to isolate and expand MSCs. The Dental drill model was applied to both knee condyles, left untreated for six weeks at which stage, PKH26 fluorescently labelled MSCs were seeded into a hyaluronic acid hydrogel (TETEC). Repair tissue was removed from both condyles and MSC-hydrogel was injected into the left knee, whilst right knee was left empty. Rabbits were sacrificed at one (n = 1), six (n = 3) and twelve (n = 3) weeks post-treatment, processed as previously described and cartilage regeneration evaluated using Sellers score3. Impacted condyles exhibited no observed changes histologically (Mean OARSI score = 1 + 1), whereas biopsy punched and dental drilled defects demonstrated equal signs of cartilage erosion (OARSI score = 3 + 1) at assessed time points. However, biopsy punched condyles formed a diffusive defect, whereas dental drilled condyles showed a more defined, compact and reproducible defect. In the pilot study, PKH-labelled MSCs were observed at one and six weeks post-implantation within the defect space where hydrogel was injected. Tissue regeneration assessment indicated no difference between empty (Mean Sellers score = 14 + 2) and MSC treated defects (Sellers score = 16 + 5) at six weeks post-injection. At twelve weeks, MSC treated defects showed improved tissue regeneration with substantial subchondral bone restoration and good integration of regenerative cartilage with surrounding intact tissue (Sellers score = 10 + 1), whereas untreated defects showed no change in regeneration compared to six weeks (Sellers score = 16 + 2). Dental drill model was found to be the appropriate strategy for investigating early OA progression and treatment. Application of MSCs in defects showed good cartilage regeneration after twelve weeks application, indicating their promise in the treatment of early OA defects

Introduction. Deformity influences the weight bearing stresses on the knee joint. Correction of mechanical alignment is performed to offload the knee and slow the rate of degenerative change. Fixator assisted deformity correction facilitates accurate correction prior to internal fixation. We present our results with standard Ilizarov and UNYCO system assisted deformity correction of the lower limb. Materials and Methods. Retrospective analysis of adult surgical cases of mechanical re-alignment performed between 2010 and 2019 in a tertiary referral centre. We recorded standard demographics and operative time from the electronic patient record. We analysed digitalised radiographs to record pre- and post-operative measurements of: Mechanical axis deviation (MAD), femoral tibial angle (FTA), Medial Proximal tibial angle (MPTA) and Mechanical lateral distal femoral angle (mLDFA). The accuracy of the correction was analysed. Time to healing, secondary interventions and complications were also recorded. Results. 7 patients underwent fixator assisted deformity correction with the UNYCO system and 11 with a standard Ilizarov frame. Mean pre-op MAD was 45.8mm in the UNYCO group and 43.4mm in Ilazrov; Mean post-op MAD was 9.5mm in the UNYCO group (5–15) and 12.3 in the Ilizarov group (1–25) p=0.07. The average surgical time in the UNYCO group was 200 minutes (128–325) and 252 minutes (203–301) in the Ilizarov group p=0.07. The mean post op MPTA was 90.2 (87–96) in the UNYCO group and 87.4 (81–94) in the Ilizarov group. The mean mLDFA was 90.0(81–93.5) in the UNYCO group and 87.3(82.2–93.9) in the Ilizarov group. All the corrections involved a plate or nail fixation and mean time to union was 76.3 days in the UNYCO and 117.3 in the Ilizarov group. Conclusions. Both systems allowed accurate correction of deformity and limb alignment. In this small series we were unable to show a difference in theatre time. The application of the principles of deformity correction are as important as the surgical methods

Background: Structural hip deformities including developmental dysplasia of the hip (DDH) and femoroacetabular impingement (FAI) are thought to predispose patients to degenerative joint changes. However, the natural history of these malformations is not clearly delineated. Methods: Seven-hundred twenty-two patients ≤55 years that received unilateral primary total hip arthroplasty (THA) from 1980–1989 were identified. Pre-operative radiographs were reviewed on the contralateral hip and only hips with Tönnis Grade 0 degenerative change that had minimum 10-year radiographic follow-up were included. Radiographic metrics in conjunction with the review of two experienced arthroplasty surgeons determined structural hip diagnosis as DDH, FAI, or normal morphology. Every available follow-up AP radiograph was reviewed to determine progression from Tönnis Grade 0–3 until the time of last follow-up or operative intervention with THA. Survivorship was analyzed by Kaplan-Meier methodology, hazard ratios, and multi-state modeling. Results: One-hundred sixty-two patients met all eligibility criteria with the following structural diagnoses: 48 DDH, 74 FAI, and 40 normal. Mean age at the time of study inclusion was 47 years (range 18–55), with 56% females. Mean follow-up was 20 years (range 10 – 35 years). Thirty-five patients eventually required THA: 16 (33.3%) DDH, 13 (17.6%) FAI, 6 (15.0%) normal. Kaplan-Meier analysis demonstrated that patients with DDH progressed most rapidly, followed by FAI, with normal hips progressing the slowest. The mean number of years spent in each Tönnis stage by structural morphology was as follows: Tönnis 0: DDH = 17.0 years, FAI = 14.8 years, normal = 22.9 years; Tönnis 1: DDH = 12.2 years, FAI = 13.3 years, normal = 17.5 years; Tönnis 2: DDH = 6.0 years, FAI = 9.7 years, normal = 8.6 years; Tönnis 3: DDH = 1.6 years, FAI = 2.6 years, normal = 0.2 years. Analysis of degenerative risk for categorical variables showed that patients with femoral head lateralization >10 mm, femoral head extrusion indices >0.25, acetabular depth-to-width index <0.38, lateral center-edge angle <25 degrees, and Tönnis angle >10 degrees all had a greater risk of progression from Tönnis 0 to Tönnis 3 or THA. Among patients with FAI morphology, femoral head extrusion indices >0.25, lateral center-edge angle <25 degrees, and Tönnis angle >10 degrees all increased the risk of early radiographic progression. Analysis of degenerative risk for continuous variables using smoothing splines showed that risk was increased for the following: femoral head lateralization >8 mm, femoral head extrusion index >0.20, acetabular depth-to-width index <0.30, lateral center-edge angle <25 degrees, and Tönnis angle >8 degrees. Conclusions: This study defines the long-term natural history of DDH and FAI in comparison to structurally normal young hips with a presumably similar initial prognostic risk (Tönnis Grade 0 degenerative change and contralateral primary THA). In general, the fastest rates of degenerative change were observed in patients with DDH. Furthermore, risk of progression based on morphology and current Tönnis stage were defined, creating a new prognostic guide for surgeons. Lastly, radiographic parameters were identified that predicted more rapid degenerative change, both in continuous and categorical fashions, subclassified by hip morphology

Fibular head avulsion fractures represent a significant injury to the posterolateral corner of the knee. There is a high rate of concomitant injuries including rupture of the cruciate ligaments. Surgical fixation is indicated to restore stability, protect repaired or reconstructed cruciate ligaments and possibly decrease the likelihood of degenerative change. The current presentation describes a novel technique which provides secure fixation to the fibular head, restoring integrity of the posterolateral ligament complex and facilitating early motion. We also present a case series of our experience by a single surgeon at our tertiary referral center. Twenty patients underwent open reduction and internal fixation between 2006 and 2016 using a large fragment cannulated screw and soft tissue washer inserted obliquely from the proximal fibula to tibia. Fixation was augmented with suture repair of the lateral collateral ligament and biceps tendon. The orientation of the fracture was assessed based on preoperative imaging. Repair / reconstruction of concomitant injuries was performed during the same procedure. Early range of motion was initiated at 2 weeks postoperatively under physical therapy guidance. All patients returned for clinical and radiographic assessment (average 3.5 years). All fractures went on to bony union. There were no reoperations for recurrent instability. All patients regained functional range of motion with mean extension of 0.94 degrees and mean flexion of 121.4 degrees. Two patients underwent hardware removal. One patient developed a late local infection, which occurred greater than 5 years after surgery. Eleven patients underwent postoperative varus stress radiographs which demonstrated less than 1 mm difference between the operated and contralateral side. Fracture morphology typically demonstrated an oblique pattern in the coronal plane and a transverse pattern in the sagittal plane. This study represents a novel surgical technique for the repair of fibular head avulsion fractures with a large fragment cannulated screw placed obliquely from the fibula to tibia. Fixation is augmented with a soft tissue washer and suture repair. Our results suggest that this technique allows for early range of motion with maintenance of reduction, high rates of union, and excellent postoperative stability

In the setting of traumatic elbow injuries involving coronoid fractures, the relative size of the coronoid fragment has been shown to relate to the stability of the joint. Currently, the challenge lies in accurately classifying the amount of bone loss in coronoid fractures. In comminuted fractures, bone loss is difficult to measure with plain radiographs or computed tomography. The purpose of this study is to describe a novel radiographic measure, the Coronoid Opening Angle (COA), on lateral elbow radiographs. We demonstrate the relationship of the COA to coronoid height and describe how this measure can be used to estimate bone loss and potentially predict elbow instability following coronoid fracture. Radiographs were drawn from a regional database in a consecutive fashion. Candidate radiographs were excluded on the basis of radiographic evidence of degenerative changes, previous surgery or injury, bony deformity, and inadequate lateral view of the elbow. The COA was measured as the angle between the long axis of the ulna at the level of the trochlear notch, and the tip of coronoid, from a common origin at the posterior cortex of the olecranon. Images were reviewed by a fellowship trained upper extremity surgeon, an upper extremity fellow, and a junior resident. Normal COA, coronoid height, and calculated COA at varying amounts of bone loss were calculated by three reviewers. A sensitivity analysis was performed to determine how the COA can most effectively predict bone loss at varying coronoid heights. Intraclass correlation coefficient (ICC) was calculated for 39 subjects. Seventy-two subjects were included for analysis (M=40, F=32). The normal coronoid opening angle is 33.19 degrees [32.2 – 34.2]. Coronoid height is 18.8 mm [18.1 – 19.6]. Extrapolating this baseline data, the COA at 20%, 33%, and 50% of coronoid bone loss was calculated to be 27.5, 23.5, and 18 degrees, respectively. ICC was found to be 0.90 or higher. Cutoff values were determined to maximize the sensitivity of the COA. A cutoff value of 21 degrees has a 92% sensitivity in detecting a minimum of 50% bone loss. The COA with similar sensitivity in predicting 20% and 33% bone loss are 32 and 27 degrees. The coronoid opening angle is a novel technique that can be used on a lateral elbow radiograph to predict the minimum coronoid bone loss. This can be used to guide clinical decision making and potentially predict instability. Future research will aim to validate this tool in the clinical setting in predicting instability

Introduction. Unicompartmental knee arthroplasty (UKA) has seen renewed interest in recent years due to improved surgical techniques and prosthetic design, and the desire for minimally invasive surgery. For patients with limited degenerative disease, UKA offers a viable alternative to total knee arthroplasty. Historically, the outcomes of lateral compartment UKA have been inferior to medial compartment UKA, with suboptimal patient satisfaction and increased revision rates. Robotic-assisted UKA has been shown to improve precision and accuracy of component placement, which may improve outcomes of lateral UKA. The purpose of this study was to compare the outcome of robotic-assisted UKA to conventional UKA for degenerative disease of the lateral compartment. The hypothesis of the study was that robotic-assisted lateral UKA results in superior outcomes compared to conventional UKA. Materials and methods. A search of the institution's joint registry was conducted to identify patients who underwent UKA for limited degenerative disease of the lateral knee compartment. A total of 130 lateral UKAs were identified that were performed between 2004 and 2012. The mean age of the patients was 63.1 years (range, 20 to 88); patients had a mean BMI of 29.9 (range, 18 to 48). The medical records of all patients were reviewed and assessed for the type of surgical procedure used (robotic-assisted versus conventional), length of hospital stay, Oxford knee score, and occurrence of revision surgery. Results. A total of 93 robotic-assisted and 37 conventional UKA were analysed. At a mean follow-up 35 months (range, 1 to 107 months), the mean Oxford scores in the robotic-assisted and conventional group were similar (39.6 versus 35.9, p=0.135). The length of stay was significantly shorter after robotic-assisted UKA (1.7 days) compared to conventional UKA (2.3 days, p<0.001). There were significantly more revisions in the conventional UKA group [6 conversions to total knee arthroplasty (TKA), 2 tibial component exchanges] compared to robotic-assisted UKA (2 conversions to TKA, p<0.001). Conclusions. The findings of this study revealed a decreased revision rate in robotic-assisted lateral UKAs compared to conventional lateral UKA. Furthermore, patients who received robotic-assisted UKAs had a shorter postoperative hospital stay compared to patients who received conventional UKA. However, overall surgical outcomes were similar in both patient cohorts based on similar postoperative Oxford scores. UKA is a technically challenging procedure with limited joint visualisation and less tolerance for acceptable component position; a two-degree error may lead to UKA failure. Malaligned components may lead to impaired joint biomechanics causing pain and disease progression to other knee compartments. Robotic-assisted UKA systems offer increased accuracy of component placement with objective soft-tissue balancing. Improved component positioning with robotic-assisted UKA systems may improve the long-term survival of UKA in patients with limited lateral degenerative disease, which is performed less often than medial UKA

Hemiarthroplasty is a common procedure that is an attractive alternative to total arthroplasty because it conserves natural tissue, allows for quicker recovery, and has a lower cost. One significant issue with hemiarthroplasties is that they lead to accelerated wear of the opposing native cartilage, likely due to the high stiffness of the implant. The purpose of this study was to investigate the range of currently available biomaterials for hemiarthroplasty applications. We employed a finite-element (FE) model of a radial head implant against the native capitellum as our joint model. The FE model was developed in ABAQUS v6.14 (Dassault Systèmes Simulia Corp., Providence, RI, USA). A solid axisymmetric concave implant with seven different materials and the native radial head were evaluated, six modelled as elastic materials with different Young's moduli (E) and Poisson's Ratios (ν), and one modelled as a Mooney-Rivlin hyperelastic material. The materials investigated were CoCr (E=230 GPa, ν = 0.3), PEEK (E=3.7 GPa, ν = 0.36), HDPE (E=2.7 GPa, ν = 0.42), UHMWPE (E=0.69 GPa, ν = 0.49), Bionate 75D (E=0.288 GPa, ν = 0.39), Bionate 55D (E=0.039 GPa, ν = 0.45), and Bionate 80A (modelled as a Mooney-Rivlin hyperelastic material). A load of 100 N was applied to the radius through the center of rotation representing a typical load through the radius. The variable of interest was articular contact stress on the capitellum. The CoCr implant had a maximum contact stress over 114% higher than the native radial head. By changing the material to lower the stiffness of the implant, the maximum contact stress was 24%, 70%, 105%, 111%, 113%, and 113% higher than the native radial head for Bionate 80A, Bionate 55D, Bionate 75D, UHMWPE, HDPE, and PEEK respectively. This work shows that lowering implant stiffness can reduce the contact stress on cartilage in hemiarthroplasty implants. By changing the material below a Young's modulus of ∼100 MPa elevated stresses on the capitellum can be markedly reduced and hence potentially reduce or prevent degenerative changes of the native articulating cartilage. Low stiffness implant materials are not a novel concept, but to date there have been few that investigate materials (such as Bionate) as a potential load bearing material for implant applications. Further work is required to assess the efficacy of these materials for articular bearing applications

Introduction. There has been renewed interest in the use of unicompartmental knee arthroplasty (UKA) for patients with limited degenerative disease of the knee due to improved surgical techniques and prosthetic design, and the desire for minimally invasive surgery. However, patient satisfaction following UKA for lateral compartment disease have been suboptimal with increased revision rates. Robotic-assisted UKA has been shown to improve precision and accuracy of component placement, which may improve outcomes of lateral UKA. The purpose of this study was to compare the outcome of robotic-assisted UKA to conventional UKA for degenerative disease of the lateral compartment with the hypothesis that robotic-assisted lateral UKA results in superior outcomes compared to conventional UKA. Methods. The institution's joint registry was searched for patients who underwent UKA for limited degenerative disease of the lateral knee compartment between 2004 and 2012 and a total of 125 lateral UKAs were identified. The medical records of all patients were reviewed and assessed for the type of surgical procedure used (robotic-assisted versus conventional), length of hospital stay, Oxford knee score, and occurrence of revision surgery. Preoperative and postoperative radiographs were assessed for tibiofemoral angle, femoral and tibial joint line angle, posterior tibial slope, and orientation of the femoral and tibial components. Results. A total of 88 (84 patients) robotic-assisted (Figure 1) and 37 (36 patients) conventional UKA (Figure 2) were analyzed and compared. Patient age and BMI were similar between patients with robotic-assisted (64.2 ± 11.5 years, 28.7 kg/m. 2. ) and conventional UKA (64.2 ± 11.5 years [p = 0.998], 30.5 kg/m. 2. [p = 0.107]). At a mean follow-up of 24.4 ± 1.1 months for robotic-assisted UKA and 64.0 ± 3.0 months (p < 0.05) for conventional UKA, the mean Oxford scores were significantly higher in patients with robotic-assisted UKA (39.4 ± 1.1 versus 34.4 ± 2.5, p = 0.048). The length of stay was significantly shorter after robotic-assisted UKA (1.7 days) compared to conventional UKA (2.3 days, p < 0.001). Correction of the tibiofemoral angle was significantly higher in patients with conventional UKA (8.7 to 176.9 degrees) compared to patients with robotic-assisted UKA (3.4 to 174.3 degrees, p < 0.001). However, the femoral component was in significantly greater varus position in conventional UKA (98.7 degrees) compared to robotic-assisted UKA (88.2 degrees, p < 0.001). There were significantly more revisions in the conventional UKA group (7 conversions to total knee arthroplasty, 2 tibial component exchanges) compared to robotic-assisted UKA (2 conversions to TKA, p < 0.001). Discussion. The findings of this study revealed a decreased revision rate in robotic-assisted lateral UKAs compared to conventional lateral UKA. Furthermore, patients who received robotic-assisted UKAs had a shorter postoperative hospital stay compared to patients who received conventional UKA. Implant orientation was improved in robotic-assisted UKA compared to conventional UKA. UKA is a technically challenging procedure with limited joint visualization and malaligned components may lead to impaired joint biomechanics causing pain and disease progression to other knee compartments. Robotic-assisted UKA systems offer increased accuracy of component placement with objective soft-tissue balancing which may improve the long-term survival of UKA in patients with limited lateral degenerative disease