Aims. Surgical treatment of young femoral neck fractures often requires an open approach to achieve an anatomical reduction. The application of a
Aims. The aim of this study was to explore why some
Aims. This study aimed to determine whether lateral femoral wall thickness (LWT) < 20.5 mm was associated with increased revision risk of intertrochanteric fracture (ITF) of the hip following sliding hip screw (SHS) fixation when the medial
Aims. The aim of this study was to estimate the 90-day risk of revision for periprosthetic femoral fracture associated with design features of cementless femoral stems, and to investigate the effect of a collar on this risk using a biomechanical in vitro model. Materials and Methods. A total of 337 647 primary total hip arthroplasties (THAs) from the United Kingdom National Joint Registry (NJR) were included in a multivariable survival and regression analysis to identify the adjusted hazard of revision for periprosthetic fracture following primary THA using a cementless stem. The effect of a collar in cementless THA on this risk was evaluated in an in vitro model using paired fresh frozen cadaveric femora. Results. The prevalence of early revision for periprosthetic fracture was 0.34% (1180/337 647) and 44.0% (520/1180) occurred within 90 days of surgery. Implant risk factors included: collarless stem, non-grit-blasted finish, and triple-tapered design. In the in vitro model, a medial
Aims. In recent years, the use of a collared cementless femoral prosthesis has risen in popularity. The design intention of collared components is to transfer some load to the resected femoral
Abstract. Objective. To estimate the effect of
The
Aims. Fixation of osteoporotic proximal humerus fractures remains challenging even with state-of-the-art locking plates. Despite the demonstrated biomechanical benefit of screw tip augmentation with bone cement, the clinical findings have remained unclear, potentially as the optimal augmentation combinations are unknown. The aim of this study was to systematically evaluate the biomechanical benefits of the augmentation options in a humeral locking plate using finite element analysis (FEA). Methods. A total of 64 cement augmentation configurations were analyzed using six screws of a locking plate to virtually fix unstable three-part fractures in 24 low-density proximal humerus models under three physiological loading cases (4,608 simulations). The biomechanical benefit of augmentation was evaluated through an established FEA methodology using the average peri-screw bone strain as a validated predictor of cyclic cut-out failure. Results. The biomechanical benefit was already significant with a single cemented screw and increased with the number of augmented screws, but the configuration was highly influential. The best two-screw (mean 23%, SD 3% reduction) and the worst four-screw (mean 22%, SD 5%) combinations performed similarly. The largest benefits were achieved with augmenting screws purchasing into the
Total hip arthroplasty (THA) allows patients to return to an active lifestyle. Unfortunately one of the more common complications of cementless THA is a fracture of the greater trochanter (GT) or the
Introduction. Segmental defects of the femur present a major problem during revision hip arthroplasty. In particular,
The
Background. Post-operative periprosthetic femoral fractures (PFF) are a devastating complication associated with high mortality and are costly. Few risk factors are modifiable apart from implant choice. The design features governing risk of PFF are unknown. We estimated the 90-day risk of revision for PFF associated with design features of cementless femoral stems and to investigate the effect of a collar on early PFF risk using a biomechanical in-vitro model. Patients, materials and methods. 337 647 primary THAs from the National Joint Registry (UK) were included in a multivariable survival and regression analysis to identify the adjusted hazard of PFF revision following primary THA using cementless stems. The effect of a collar in cementless THA on early PFF was evaluated in an in-vitro model using paired fresh frozen cadaveric femora. Results. Prevalence of PFF revision was 0.34% (1180/337647) and 44.0% occurred (520/1180) within 90 days of surgery. Implant risk factors included: collarless stem, non grit-blasted finish and triple tapered design. In the in-vitro PFF model a medial
Metal meshes are used in revision surgery of the hip to contain impacted bone grafts in cases with cortical or
Background: The
Resorption of the
Resorption of the
Between January 1990 and October 2000, 108 total hip arthroplasties using a cemented polished titanium stem and a cemented ultra-high molecular weight polyethylene (UHMWP) cup were performed at our hospital. Because during routine follow-up visits we noted instances of resorption of the
We have previously reported on early lytic lesions occurring when collared titanium prostheses are used. Previous finite element analysis studies (FEAs) showed that lytic lesions of the
The aim of this retrospective study was to assess the incidence of early periprosthetic femoral fracture (PFF) associated with Charnley-Kerboull (CK) femoral components cemented according to the ‘French paradox’ principles through the Hueter anterior approach (HAA) in patients older than 70 years. From a prospectively collected database, all short CK femoral components implanted consecutively from January 2018 to May 2022 through the HAA in patients older than 70 years were included. Exclusion criteria were age below 70 years, use of cementless femoral component, and approaches other than the HAA. A total of 416 short CK prostheses used by 25 surgeons with various levels of experience were included. All patients had a minimum of one-year follow-up, with a mean of 2.6 years (SD 1.1). The mean age was 77.4 years (70 to 95) and the mean BMI was 25.3 kg/m2 (18.4 to 43). Femoral anatomy was classified according to Dorr. The measured parameters included canal flare index, morphological cortical index, canal-calcar ratio, ilium-ischial ratio, and anterior superior iliac spine to greater trochanter (GT) distance.Aims
Methods
A consensus regarding management of calcaneal fractures eludes orthopaedic surgeons. While operative treatment has gained more acceptance, surgical morbidity remains high. We undertook a retrospective review of early complications and radiological outcomes following internal fixation of calcaneal fractures in our unit over 15 months. A consecutive series of 33 patients who underwent fixation of the
Introduction and Aims: Rapidly progressive lytic lesions of the
Purpose: The success of humeral head replacement following fracture is reliant on several factors, one of which is version. The correct humeral version (HV) is highly variable, and is patient and side dependent. In the setting of fracture, there is no intra-operative landmark to guide the surgeon as to the anatomic version. This study has examined computed tomography (CT) of the shoulder and compared the HV to the metaphyseal version (MV) to evaluate reliability in predicting the anatomic version. Method: A retrospective review of 50 shoulder CT scans was carried out. Patients were excluded if the anatomy prevented HV or MV evaluation. The HV and MV was measured by 2 independent evaluators. Inter and intra-rater reliability was performed. Results: There were 27 right and 23 left shoulder CT’s reviewed. The mean age of patients was 45.3 (range 13–85). The difference between the MV and HV was approximately 2.8 (95% CI 0.63–5.1). Inter and intra-rater reliability was 0.966 and 0.984, respectively. Conclusion: Determining the version of the humeral head in the setting of fracture is difficult and highly inaccurate. The biceps groove has been previously cited as a landmark for arthroplasty position, however, given the anatomic variability, version may be miscalculated. We have demonstrated the medial
Aim: To evaluate long term effects of stress shieldieng phenomenon after cementless total hip arthroplasty. Materials-Methods: 80 female pts with OA were randomly allocated in 4 groups according to the type of the cementless stem which was primarily implanted (A-Zwey-Muller,B-Corail,C- Optifix,DAutophor900S). BMD changes of the operated hip (in seven zones), of the operated, contralateral normal hip and of the Lumbar spine were measured pre-op, at 2, 8 and 12 months and every year thereafter. Results: At ten years, 72 pts were available for follow up, all with satisfactory clinical and radiological results with no evidence of polyethylene wear or endosteal lysis. In all groups, the greatest reduction of BMD (calcar atrophyzone 7) was observed at the 2nd post-op year (A:24%, B:8%, C:14.8%, D:18.5%). In all groups, the greatest increase (zone 4) of BMD was also observed at the 2nd post-op year (A7%, B2%, C2.5%, D6.3%). In all groups a similar pattern of slow but progressive recovery of bone mineral density changes after the 3rd year was observed in both zones, approaching baseline values at 10 years in all groups. Preoperative lumbar BMD (osteopenia), body weight, sex and height were not statisticaly correlated to
Chronic osteomyelitis of the calcaneus is a frequent problem in a population of diabetic patients, patients with neurologic disorders or bedridden patients with ulcers. Partial calcanectomy is an alternative option which avoid major amputation. The aim of this retrospective study was to determine the effectiveness of partial calcanectomy for treating chronic osteomyelitis of the calcaneux. We conducted a retrospective review of patients who underwent in our department a partial calcanectomy between 2006 and 2015. All patients with a complete set of radiographs and adequate follow-up (minimum 2 years) were included. We reviewed these cases to determine healing rate, microbiological analysis, risk factors of failure (comorbidities), limb salvage rate and survival rate. We analyzed specifically the footwear and the functional subjective evaluation according to the LEFS score (Lower Extremity Functional Scale).Aim
Method
1. The literature on fractures of the postero-superior aspect of the calcaneus is reviewed. 2. The mechanical distinction between "beak" fractures and avulsion fractures is questioned, and the dangers of a purely radiological diagnosis are stressed. 3. When a complete avulsion is suspected on clinical grounds, open reduction should be done.
1. Five cases of avulsion fracture of the calcaneus are reported. 2. The "beak" fracture of the calcaneus is thought to be a variant of the avulsion fracture and not a separate entity. 3. The variable attachment of the calcaneal tendon to the calcaneus is described, and its relationship to the different forms of avulsion fractures discussed. 4. Operative reduction and fixation are appropriate for young and active patients in order to restore full heel-cord function. 5. Attention is drawn to the risk of pressure necrosis of skin overlying a displaced fragment. Early operative correction may be required to prevent skin damage.
1. The clinical aspects of fifty-six patients with rupture of the tendo calcaneus are discussed, and the mechanism of injury is described. 2. Operative repair of the rupture is considered with a study of the results in twenty-eight patients.
1. Twenty patients with congenital short tendo calcaneus are described. 2. All were treated by tendon lengthening and followed up for one and a half to seven years.
We reviewed our experience of tibialis anterior transfer and anterior release for calcaneus deformity in 46 feet of 26 ambulant patients with myelomeningocele. At an average follow-up of 8.4 years (2 to 17.6) there were 89% who had satisfactory results; 64% of the patients having tibialis anterior transfers were able to stand on their toes. Hip abductor power was a good predictor of a functional transfer. Pre-operative trophic ulceration of the heel increased from 3.2% to 33% if surgery was delayed. Secondary deformities, two-thirds of them into valgus, developed in 76% of feet.
The thalamus is the part of the calcaneus that supports the posterior articular facet and continues forward, becoming thinner towards the groove of the sinus tarsi. The main displacements after fracture depend on 1) a primary fracture line dividing the bone into anterior and posterior fragments, and 2) a semilunar fragment in the thalamic region. In the operation advised the sinus tarsi is exposed and the semilunar fragment is reduced by rotation in the opposite direction and is fixed to the medial fragment (the sustenaculum tali not being displaced) by a transverse Kirschner wire. The two main fragments are fixed by an antero-posterior wire. Plaster is applied and is retained for twelve weeks. Weight-bearing is not permitted for the first four weeks. There were no major complications in fifty-eight operations. The anatomical results were good: restoration of the tuber-joint angle by reduction of the semilunar fragment was maintained. The functional results were very satisfactory: permanent disability was slight or mild.
1 . Paralytic talipes calcaneus and calcaneo-cavus are difficult deformities to correct and keep corrected. Many operations have been devised for this purpose. 2. Emslie's operation is a simple procedure by which satisfactory correction can be obtained and maintained. It can be modified to suit individual cases without altering the basic principles of the procedure and is physiologically sound. 3. Illustrative cases are described.
1. In a severe crush fracture of the calcaneus part of the lateral cortex may be displaced to lie under the tip of the lateral malleolus. This may cause local pain and tenderness, either by direct bony abutment or by compression of the peroneal tendons. 2. Such pain is usually relieved by excision of the tip of the lateral malleolus, a minor procedure. 3. Four of the five patients reported were completely relieved of lateral pain, and the fifth has only slight residual discomfort. 4. It is important to be aware of this lesion and not to advise subtalar or triple fusion when simple excision of the tip of the fibula would suffice.
1. A case of ossification and partial rupture of the tendo calcaneus is reported. 2. The possible etiology of the ossification and its relationship to the rupture is discussed.
Bony tumours of the foot account for approximately 3% of all osseous tumours. However, literature regarding os calcis tumours comprises individual case reports, short case series or literature reviews, with the last large case series in 1973. We retrospectively reviewed the medical notes and imaging for all patients with calcaneal tumours recorded in the Scottish Bone Tumour Registry since the 1940's. Demographics, presentation, investigation, histology, management and outcome were reviewed. 38 calcaneal tumours were identified. Male to female ratio 2:1, mean age at presentation 30 with heel pain and swelling, average length of symptoms 9 months. 4 cases present with pathological fracture. 24 tumours benign including 6 unicameral bone cysts, 3 chondroblastoma, 3 PVNS with calcaneal erosion, and a wide variety of individual lesions. 13 malignant tumours comprising 6 osteosarcoma, 5 chondrosarcoma and 2 Ewings sarcoma. 1 metastatic carcinoma. Tumours of the calcaneus frequently are delayed in diagnosis due to their rarity and lack of clinician familiarity. They are more common in men and have a 1 in 3 risk of malignancy, covering a wide variety of lesions. Outcome is dependent on early diagnosis, timely surgery and most importantly neo-adjuvant chemotherapy. Diagnosis is often made on plain radiograph but MRI is the gold standard. We present the largest case series of calcaneal tumours, from our experience with the Scottish Bone Tumour Registry. Despite their rarity clinicians should maintain a high index of suspicion as accurate and timely diagnosis is important to management and outcome.
The Ilizarov fixator used consisted of 2 rings positioned above the ankle joint and a foot plate. 1.5 and 1.8 mm wires were used, as well as 1.8 mm wires with an olive for the reduction of displaced fragments. Under image intensification and distraction the fracture was reduced and the articular surface was restored as close as possible.
Controversy exists regarding the management of intra-articular fractures of the calcaneus. We present medium-term outcome data on 37 consecutive patients who underwent open reduction and internal fixation for comminuted intra-articular calcaneal fractures. Operations were performed by one surgeon, CRW, following CT assessment of the fracture. All procedures were performed using an extensile lateral approach and early physiotherapy was standard. Case notes were reviewed retrospectively between three months and five years post-operatively. Patients were also invited to attend a follow-up clinic where outcomes were assessed using the American Orthopaedic Foot and Ankle Society Hind Foot Score and were questioned regarding on-going problems, change in shoe size and return to work. Complete data is available for 16 patients, with additional information from other patients. Results show average AOFAS scores for type II fractures to be 59/100, type III to be 81/100 and 79/100 for type IV fractures. We have shown low rates of complications – one infection, three patients requiring a change in shoe size and an average return to work of seven months. We have shown good medium-term outcome results for the operative management of displaced intra-articular fractures and to answer our question, we believe we should be operating on them.
The lack of a universal, consistent protocol for the subjective, objective and radiographic evaluation of these injuries has hampered the comparison of results. 45 patients with complex fractures of the calcaneus were included in this prospective study, which was undertaken from July 2003 to December 2005. The fracture classification of Essex-Lopresti was used. We also observed the extent of secondary fracture lines extending from the primary shear line (on axial and external oblique plain radiographs) to establish comminution. The external oblique view for subtalar joint was performed with the patient supine, the knee at about 60 degree of flexion and the limb rotated externally 45 degree with a vertical X ray beam. All of these patients were managed by an external fixator using the principle of ligamentotaxis. Patients were evaluated by AOFAS. We identified two broad patterns of secondary lines on plain X-rays: with anterior secondary fracture lines and with posterior secondary fracture lines. There were 20 cases of tongue type and 25 of joint depression type fracture pattern by the Essex-Lopresti classification. Forty two (93.4%) patients had fractures with posterior secondary fracture line and 3 (6.7%) patients had anterior secondary lines. The calcaneo-cuboid type of anterior secondary line pattern was present in 2 (4.5%) cases, and the plantar type in only 1 (2.5%) case. We observed posterior secondary line Type A pattern in 2 (4.5%) cases, depression / central depression type B in 20 (44.5%) cases, tongue shaped Type C pattern in 16 (36.5%) cases and Type D severely comminuted fracture line pattern in 4 (8.7%) cases.Methods
Results
Böhler’s historical tuber-joint angle of the calcaneus has been used since 1931. Surprisingly, there is a paucity of literature on the topic. The aims of this study were to confirm the normal range for Böhler’s angle and determine the angle with the highest accuracy in the diagnosis of calcaneal fractures. A retrospective cohort study was performed. Data were obtained from The St George Hospital digital Picture Archival and Communication System (PACS) and through a review of medical records. The study cohort comprised 212 consecutive patients diagnosed with calcaneal fractures on CT scan, spanning a five-year period from April 2003 to March 2008. An additional 212 patients with normal lateral foot radiographs were used to determine the normal range. Böhler’s angle was measured by two independent observers on lateral xray using the digital angle tool from PACS. Data were analysed using Stata 8 statistical software package. This is the largest study to our knowledge that examines the diagnostic accuracy of Böhler’s angle in fractures of the calcaneus. Contrary to many texts but true to Böhler’s assertions, the mean Böhler’s angle in patients without calcaneal fracture was 29.4 degrees (95% CI, 28.9–30.0 degrees). In this group there was no difference in Böhler’s angle between male and female patients (p>
.05), left and right feet (p>
.05) or across age (ANOVA, p>
.05). In those patients with calcaneal fractures, a Böhler’s angle below 25 degrees was moderately predictive of calcaneal fracture (sensitivity = 100%, specificity = 82%, PPV = 85%, NPV = 100%, LR+ = 5), an angle below 23 degrees was highly predictive of calcaneal fracture (sensitivity = 100%, specificity = 89%, PPV = 90%, NPV = 100%, LR+ = 9) and an angle below 21 degrees was strongly suggestive of calcaneal fracture (sensitivity = 99%, specificity = 99%, PPV = 99%, NPV = 99%, LR+ = 110). A Böhler’s angle of less than or equal to 20 degrees had the highest diagnostic accuracy as there were only two false negatives and one false positive from a total of 424 patients. A Böhler’s angle of 20 degrees or less is highly accurate in determining the presence or absence of calcaneal fracture. These findings are of particular importance when fracture is uncertain as it gives the surgeon a definitive reference point when using Böhler’s angle for assessment of fracture of the calcaneus.
We present our experience of using tension band plates to achieve guided growth in children for correction of calcaneus deformity of the ankle. 11 consecutive patients (13 ankles) fulfilled the inclusion criteria over a 4-year period. All underwent surgical treatment using a flexible two hole plate and screws on the posterior aspect of distal tibial physis. Measurements were done on preoperative, intraoperative screening and 1-year post operative plain AP and lateral ankle radiographs. The anterior distal tibia angle (ADTA), lateral distal tibial angle (LDTA) and screw divergence angle (angle subtended by lines passing through the long axis of the screws) were used to assess the deformity correction. A 2 tailed student t-test was carried out on the initial and 1-year post-op measurements to determine statistical significance with a p value <0.05 considered as significant There were 10 residual clubfoot deformities, 2 post-traumatic deformities and 1 spinal tumor causing deformity. The average age of the patients was 10 years 5 months (range 4 to 13 years). There were 9 males and 2 females. The ADTA showed a statistically significant change with a p value of 0.0008 with a mean correction of 8.6 degrees (range of 2.3 to 15.6 degrees). The SDA demonstrated a mean correction of 15.4 degrees (range 0.3 to 41.8 degrees), p=0.002. The LDTA did not change significantly (p= 0.08), thus confirming no coincidental coronal plane deformity had occurred. 5 ankles required revision of fixation due to metalwork reaching its maximum limit of divergence at an average of 1 year. 2 ankles had screw pulled out due to osteolysis around the screw. There were no cases of infection. We report satisfactory short-term results of correction of calcaneus deformity using a flexible tension band plate and screws system.
1. Thirty-four cases of calcaneal osteotomy for mobile flat foot in nineteen patients are reviewed. 2. The function was markedly improved in seventeen of the nineteen patients. 3. The operation was successful in correcting the valgus deformity of the heel in thirty of the thirty-four feet. it was less successful in improving the longitudinal arch, especially when the flat foot deformity was severe.
Open reduction and reconstruction with osseous grafts (autologous grafts in 22 cases and heterologous grafts in 52 cases) were used in 74 cases. In 8 cases (all of Bohler II type) grafts weren’t used. Osteosynthesis with plate and screws was performed in 26 cases and with pins in 56. The 2 groups were similar in what concerns age, sex ratio, BMI, degree of comminution. The surgical procedure was delayed in both groups (average − 6 days). Pins were removed at 6 weeks and the plates at 12 months.
There are many reports of treatment for intraarticular fractures of the calcaneus using different methods. Results are very difficult to compare. For this reason a prospective study was designed to compare the outcome of the same type of fracture treated with Stein-mann pinning or plate osteosynthesis. Between January 1995 and March 1999 31 patients with two-part intraarticular fractures of the calcaneus, type IIB according to the Sanders classification, were treated operatively with either transcalcaneal pinning (12 fractures) or with open reduction and internal plate and screw fixation using a lateral approach (19 fractures). After a mean follow-up of 26 months all patients were assessed. A comparison was made between the two modes of treatment. The global score averaged 78.3 ± 12.1; 79.3 ± 11.14 for the patients treated with plate and screw fixation, and 76.6 ± 13.2 for the patients who underwent pinning. Lateral X-rays showed no difference in anatomical reduction between both methods. A positive correlation was demonstrated between the AOFAS Ankle-Hindfoot score and Böhler’s angle. The restoration of the congruity of the posterior subtalar joint was assessed postoperatively by means of a CT scan. The angle between the undersurface of the talus and the lateral fragment of the two-part fracture was evaluated. No statistically significant difference was found between both groups. The authors conclude that there is no difference in functional outcome between both modes of treatment. Plate osteosynthesis has the advantage that the shape of the hindfoot and midfoot is restored, but the higher complication rate is a drawback.
1. Thirty-three children with thirty-eight feet affected by a cavo-varus deformity and treated by calcaneal osteotomy with concomitant stripping of plantar muscles were reviewed two to ten years after operation. 2. Out of twenty-six patients who were over eleven years old at the time of the review, fourteen (with eighteen feet) did not need any further treatment. In three other patients the deformity had recurred to a slight degree but did not warrant tarsal reconstruction. In the remaining nine patients the recurrence was marked and necessitated tarsal reconstruction. 3. The combined procedure is of value when there is progressive deformity in children too young for tarsal reconstruction.
Displaced intra-articular fractures of the calcaneus need anatomic reduction of the joint surfaces and overall shape to restore function and minimize the risk of posttraumatic subtalar arthritis. The morbidity associated with extended approaches is a major concern. In the present study we compared the medium-term results after percutaneous reduction and screw fixation (PRSF) with that of open reduction and internal fixation (ORIF) for displaced fractures with less severe fracture patterns (Sanders type II).
Reduction was performed by an extended lateral approach, and checked under fluoroscopy. Joint reduction was fixed by screws. The reconstruction plate, bent in a standard way, was then placed laterally, from above the tuberosity towards the inferolateral part of the anterior process. All but one or two posterior screws ideally converge to the sustentaculum tali (ST), building a strong support below the posterior facet. Postoperatively partial weight bearing below the threshold of pain was allowed in the majority of cases. Clinical results were assessed using the French Orthopaedic Society (SOFCOT) functional score for both series, and AOFAS (American Foot and Ankle Society) score, and Mary-land Foot Score (MFS) for the recent series.
Reduction was assessed anatomic on the postoperative Broden view in 90.5% of cases. The average Böhler’s angle remained stable. Secondary fusion of the subtalar joint was required only in 4 cases (2.1%). Wound healing was delayed in 19.7%, but generally, it was spontaneously obtained in a few weeks. Three deep late infections (1.6%) healed after plate removal.
Previous studies have highlighted differences in the risk of periprosthetic fracture between tapered slip (TS) and composite beam (CB) stems. This biomechanical study explored periprosthetic fractures around these stems and the effect of adding a 16-gauge
The significance of periprosthetic fractures about a total hip arthroplasty (THA) is becoming increasingly important. Recent studies have demonstrated post-operative periprosthetic fracture rates are higher amongst cemented polished taper slip (PTS) stem designs compared to collared cementless (CC) designs. However, in the National Joint Registry, the rate of intra-operative periprosthetic femoral fractures (IOPFF) with cementless implant systems remains higher (0.87% vs 0.42%. p <0.001) potentially leading to more post-operative complications. This study identifies the incidence of IOPFF, the fracture subtype and compares functional outcomes and revision rates of CC femoral implants with an IOPFF to CC stems and PTS stems without a fracture. 5376 consecutive CC stem THA, carried out through a posterior approach were reviewed for IOPFF. Each fracture was subdivided into
Abstract. Objective. To estimate the effect of
Aims. Hip arthroplasty does not always restore normal anatomy. This is due to inaccurate surgery or lack of stem sizes. We evaluated the aptitude of four total hip arthroplasty systems to restore an anatomical and medialized hip rotation centre. Methods. Using 3D templating software in 49 CT scans of non-deformed femora, we virtually implanted: 1) small uncemented calcar-guided stems with two offset options (Optimys, Mathys), 2) uncemented straight stems with two offset options (Summit, DePuy Synthes), 3) cemented undersized stems (Exeter philosophy) with three offset options (CPT, ZimmerBiomet), and 4) cemented line-to-line stems (Kerboul philosophy) with proportional offsets (Centris, Mathys). We measured the distance between the templated and the anatomical and 5 mm medialized hip rotation centre. Results. Both rotation centres could be restored within 5 mm in 94% and 92% of cases, respectively. The cemented undersized stem performed best, combining freedom of stem positioning and a large offset range. The uncemented straight stem performed well because of its large and well-chosen offset range, and despite the need for cortical bone contact limiting stem positioning. The cemented line-to-line stem performed less well due to a small range of sizes and offsets. The uncemented calcar-guided stem performed worst, despite 24 sizes and a large and well-chosen offset range. This was attributed to the
Known risk factors for early periprosthetic femur fracture (PFF) following total hip arthroplasty (THA) include poor bone quality, surgical approach and cementless implants. The association between femoral component size and alignment and the risk of early PFF is not well described. We evaluated radiographic parameters of femoral component sizing and alignment as risk factors for early PFF. From 16,065 primary cementless THA, we identified 66 cases (0.41%) of early PFF (<90 days from index THA) at a single institution between 2016–2020. The stem was unstable and revised in all cases. We matched 60 cases of early PFFs (2:1) to 120 controls based on femoral component model, offset, surgical approach, age, BMI, and sex. Mean age was 67 years; 60% were female. Radiographic assessment of preoperative bone morphology and postoperative femoral component parameters including stem alignment, metaphyseal fill, and medial congruence with the
A: - determine the incidence of intraoperative periprosthetic femoral fracture (PFF). B: - determine the incidence of, and the reoperation rate for postoperative PFF. When using either CC or PTS femoral components. Retrospective review of a consecutive series of 11,018 THAs over a ten-year period. All PFFs were identified using regional radiograph archiving and electronic care systems. Of the 11,018 THAs 4,952 were CC and 6,066 were PTS. Between groups, age, sex, and BMI did not differ. A: - 55 (0.5%) had an intraoperative PFF. 44 CC and 11 PTS (p<0.001). 3 patients in each group had a femoral shaft fracture, remaining fractures were either the
There is a strong association between the presence of a
Proximal humeral fractures occur frequently, with fixed angle locking plates often being used for their treatment. However, the failure rate of this fixation is high, ranging between 10 and 35%. Numerous variables are thought to affect the performance of the fixation used, including the length and configuration of screws used and the plate position. However, there is currently limited quantitative evidence to support concepts for optimal fixation. The variations in surgical techniques and human anatomy make biomechanical testing prohibitive for such investigations. Therefore, a finite element osteosynthesis test kit has been developed and validated - SystemFix. The aim of this study was to quantify the effect of variations in screw length, configuration and plate position on predicted failure risk of PHILOS plate fixation for unstable proximal humerus fractures using the test kit. Twenty-six low-density humerus models were selected and osteotomized to create a malreduced unstable three-part fracture AO/OTA 11-B3.2 with medial comminution which was virtually fixed with the PHILOS plate. In turn, four different screw lengths, twelve different screw configurations and five plate positions were simulated. Each time, three physiological loading cases were modelled, with an established finite element analysis methodology utilized to evaluate average peri-screw bone strain, this measure has been previously demonstrated to predict experimental fatigue fixation failure. All three core variables lead to significant differences in peri-screw strain magnitudes, i.e. predicted failure risk. With screw length, shortening of 4 mm in all screw lengths (the distance of the screw tips to the joint surface increasing from 4 mm to 8 mm) significantly (p < 0 .001) increased the risk of failure. In the lowest density bone, every additional screw reduced failure risk compared to the four-screw construct, whereas in more dense bone, once the sixth screw was inserted, no further significant benefit was seen (p=0.40). Screw configurations not including
To identify the demographics, mechanisms of injury and treatment modalities of patients presenting at CHBAH with calcaneal fractures. A retrospective study of all admitted patients with calcaneal fractures from 01 January 2018 to 31 December 2022. The data collected includes age, gender, side of injury, mechanism of injury, isolated injury versus polytrauma, open and close fractures, different treatment modalities and time to surgery. The descriptive data will be analysed, with results presented as frequency charts, histograms, and percentages. A total of 98 patients showed a male predominance of 90.8% compared to 9.2% of females. The median age was 38 years, the commonest mechanism was from falls from height, accounting for 67.3% with gunshot injuries accounting for 5%. Bilateral fractures were observed in 5 patients, with similar total numbers between those isolated to the left (47) as compared to the injuries isolated to the right side (46).
Hip and knee joint arthroplasty wait list has been getting outrageously long in South Africa with some tertiary hospital reporting more than 5 years of waiting time. This has been further compounded by covid 19 pandemic. There is plateau of ideas on how best to address the backlogs in high volume tertiary centers, with catchup list, out reach program, private partnership seeming unsustainable. We sought to look for sustainable solution to the problem and we looked not far but inside the system. Method. Triggered by the fire that engulfed part of the hospital, we found ourself refuged at the sister tertiary hospital with no access to theatre time. We visited districts hospitals within the cluster and discovered state of the art facility underutilized. We presented a plan to establish a satellite arthroplasty center which was greatly embraced by the management. We partnered with the trade to setup an arthroplasty service in this district hospital. Employed 3 retired nurses and 2 parttime anaesthetist all on yearly contract. We developed pathways for patient selection according to American Society of Anaesthesiologist(ASA). 232 total joint arthroplasties were performed in 15-month, 33%Hips and 67%Knees. The average hospital stay was 2,3± 2days. We had 1 mortality(# NOF) and 2 cases of PJI treated successfully with debridement antibiotic and implant retention. We had 5 cases of intraoperative
Femoral stem design affects periprosthetic bone mineral density (BMD), which may impact long term survival of cementless implants in total hip arthroplasty (THA). The aim of this study was to examine proximal femoral BMD in three morphologically different uncemented femoral stems designs to investigate whether one particular design resulted in improved preservation of BMD. 119 patients were randomized to receive either a proximally coated dual taper wedge stem, a proximally coated anatomic stem or a fully coated collarless triple tapered stem. Dual energy x-ray absorptiometry scans (Lunar iDXA, GE Healthcare, Madison, WI) assessed BMD across the seven Gruen zones pre-operatively, and post-operatively at 6-weeks, 1-year, and 2-years comparing the unoperated contralateral femur as a control. BMD increased in zones one (2.5%), two (17.1%), three (13.0%), five (10%) and six (17.9%) for all stems. Greater preservation of BMD was measured on the lateral cortex (zone 2) for both the dual taper wedge and anatomic stems (p = 0.019). The dual taper wedge stem also demonstrated preservation of BMD in the medial
To be able to assess the biomechanical and functional effects of ankle injury and disease it is necessary to characterise healthy ankle kinematics. Due to the anatomical complexity of the ankle, it is difficult to accurately measure the Tibiotalar and Subtalar joint angles using traditional marker-based motion capture techniques. Biplane Video X-ray (BVX) is an imaging technique that allows direct measurement of individual bones using high-speed, dynamic X-rays. The objective is to develop an in-vivo protocol for the hindfoot looking at the tibiotalar and subtalar joint during different activities of living. A bespoke raised walkway was manufactured to position the foot and ankle inside the field of view of the BVX system. Three healthy volunteers performed three gait and step-down trials while capturing Biplane Video X-Ray (125Hz, 1.25ms, 80kVp and 160 mA) and underwent MR imaging (Magnetom 3T Prisma, Siemens) which were manually segmented into 3D bone models (Simpleware Scan IP, Synopsis). Bone position and orientation for the Talus,
Femoral stem design affects periprosthetic bone mineral density (BMD), which may impact long term survival of cementless implants in total hip arthroplasty (THA). The aim of this study was to examine proximal femoral BMD in three morphologically different uncemented femoral stems designs to investigate whether one particular design resulted in improved preservation of BMDMethods: 119 patients were randomised to receive either a proximally coated dual taper wedge stem, a proximally coated anatomic stem or a fully coated collarless triple tapered stem. All surgeries were performed via the posterior approach with mobilization on the day of surgery. Dual energy x-ray absorptiometry scans (Lunar iDXA, GE Healthcare, Madison, WI) assessed BMD across the seven Gruen zones pre-operatively, and post-operatively at 6-weeks, 1-year, and 2-years and compared to the unoperated contralateral femur as a control. Patient reported outcome measures of pain, function and health were also included at these corresponding follow-ups. BMD increased in zones one (2.5%), two (17.1%), three (13.0%), five (10%) and six (17.9%) for all stems. Greater preservation of BMD was measured on the lateral cortex (zone 2) for both the dual taper wedge and anatomic stems (p = 0.019). The dual taper wedge stem also demonstrated preservation of BMD in the medial
Background. In recent years, ‘Get It Right First Time (GIRFT)’ have advocated cemented replacements in femoral part of Total hip arthroplasty (THA) especially in older patients. However, many studies were unable to show any difference in outcomes and although cemented prostheses may be associated with better short-term pain outcomes there is no clear advantage in the longer term. It is not clear when and why to do cemented instead of cementless. Aim. To assess differences in patient reported outcomes in uncemented THAs based on patient demographics in order to decide when cementless THA can be done safely. Method. Prospective data collection of consecutive 1079 uncemented THAs performed for 954 patients in single trust between 2010 and 2020. Oxford Hip Score (OHS) and complications were analysed against demographic variables (age, sex, BMI, ASA) and prosthesis features (femoral and acetabular size, offset and acetabular screws). Results. The mean pre-operative OHS was 14.6 which improved to 39.0 at 1 year follow up (P Value=0.000). There was no statistically significant difference between OHS outcome in patients aged over 70 versus younger groups. With a small number of revisable complications increase with age from 50s upwards. Male patients’ OHS score was on average 2.4 points higher than women. Men, however were 2.9 times more likely to experience fractures and high offset hips were 2.5 times more likely to experience dislocations. DAIR, intraoperative
Aims. We compared implant and patient survival following intraoperative periprosthetic femoral fractures (IOPFFs) during primary total hip arthroplasty (THA) with matched controls. Patients and Methods. This retrospective cohort study compared 4831 hips with IOPFF and 48 154 propensity score matched primary THAs without IOPFF implanted between 2004 and 2016, which had been recorded on a national joint registry. Implant and patient survival rates were compared between groups using Cox regression. Results. Ten-year stem survival was worse in the IOPFF group (p < 0.001). Risk of revision for aseptic loosening increased 7.2-fold following shaft fracture and almost 2.8-fold after trochanteric fracture (p < 0.001). Risk of periprosthetic fracture of the femur revision increased 4.3-fold following calcar-crack and 3.6-fold after trochanteric fracture (p < 0.01). Risk of instability revision was 3.6-fold after trochanteric fracture and 2.4-fold after
Proximal humerus fractures (PHF) are the third most common fractures in the elderly. Treatment of complex PHF has remained challenging with mechanical failure rates ranging up to 35% even when state-of-the-art locked plates are used. Secondary (post-operative) screw perforation through the articular surface of the humeral head is the most frequent mechanical failure mode, with rates up to 23%. Besides other known risk factors, such as non-anatomical reduction and lack of medial cortical support, in-adverse intraoperative perforation of the articular surfaces during pilot hole drilling (overdrilling) may increase the risk of secondary screw perforation. Overdrilling often occurs during surgical treatment of osteoporotic PHF due to minimal tactile feedback; however, the awareness in the surgical community is low and the consequences on the fixation stability have remained unproved. Therefore, the aim of this study was to evaluate biomechanically whether overdrilling would increase the risk of cyclic screw perforation failure in unstable PHF. A highly unstable malreduced 3-part fracture was simulated by osteotomizing 9 pairs of fresh-frozen human cadaveric proximal humeri from elderly donors (73.7 ± 13.0 ys, f/m: 3/6). The fragments were fixed with a locking plate (PHILOS, DePuy Synthes, Switzerland) using six proximal screws, with their lengths selected to ensure 6 mm tip-to-joint distance. The pairs were randomized into two treatment groups, one with all pilot holes accurately predrilled (APD) and another one with the boreholes of the two
Introduction. Proximal short stems have gained in popularity for perceived bone preservation but more recently, physiological loading. We report the medium term success of a
INTRODUCTION. Historically, the clinical performance of novel implants was usually reported by designer surgeons who were the first to acquire clinical data. Regional and national registries now provide rapid access to survival data on new implants and drive ODEP ratings. To assess implant performance, clinical and radiological data is required in addition to implant survival. Prospective, multi-surgeon, multi-centre assessments have been advocated as the most meaningful. We report the preliminary results of such a study for the MiniHip™femoral component and Trinity™ acetabular component (Corin Ltd, UK). METHODS. As part of a non-designer, multi-surgeon, multi-centre prospective surveillance study to assess the MiniHip™stem and Trinity™ cup, 535 operations on 490 patients were undertaken. At surgery, the average age and BMI of the study group was 58.2 years (range 21 to 76 years) and 27.9 (range 16.3 to 43.4) respectively. Clinical (Harris Hip Score, HHS) and radiological review have been obtained at 6 months, 3 and 5 years. Postal Oxford Hip Score (OHS) and EuroQol- 5D (EQ5D) score have been obtained at 6 months and annually thereafter. To date, 23 study subjects have withdrawn or lost contact, 11 have died, and 9 have undergone revision surgery. By the end of March 2018, 6 month, 1, 2, 3, 4, and 5 year data had been obtained for 511, 445, 427, 376, 296 and 198 subjects respectively. RESULTS. Implant revision rate is 1.68% (9/535), with revision for any reason as an endpoint; four of the nine involved the revision of the femoral component. At the 5-year time point, mean OHS had improved from 21.3 to 42.5 (p<0.01), EQ5D from 0.42 to 0.82 (p<0.01), and HHS from 51.6 to 92.5 (p<0.01). Radiological analysis is ongoing, and thus far has revealed more variation in stem alignment than is usually observed for more conventional length femoral components. This may indicate that optimal alignment of
Aims. Shoulder arthroplasty using short humeral components is becoming increasingly popular. Some such components have been associated with relatively high rates of adverse radiological findings. The aim of this retrospective review was to evaluate the radiological humeral bone changes and mechanical failure rates with implantation of a short cementless humeral component in anatomical (TSA) and reverse shoulder arthroplasty (RSA). Patients and Methods. A total of 100 shoulder arthroplasties (35 TSA and 65 RSA) were evaluated at a mean of 3.8 years (3 to 8.3). The mean age at the time of surgery was 68 years (31 to 90). The mean body mass index was 32.7 kg/m. 2. (17.3 to 66.4). Results. Greater tuberosity stress shielding was noted in 14 shoulders (two TSA and 12 RSA) and was graded as mild in nine, moderate in two, and severe in three. Medial
Treatment of proximal humerus fractures (PHF) is controversial in many respects, including the choice of surgical approach for fixation when using a locking plate. The classic deltopectoral (DP) approach is believed to increase the risk of avascular necrosis while making access to the greater tuberosity more difficult. The deltoid split (DS) approach was developed to respect minimally invasive surgery principles. The purpose of the present study (NCT-00612391) was to compare outcomes of PHF treated by DP and DS approaches in terms of function (Q-DASH, Constant score), quality of life (SF12), and complications in a prospective randomized multicenter study. From 2007 to 2016, all patients meeting the inclusion/exclusion criteria in two University Trauma Centers were invited to participate in the study. Inclusion criteria were: PHF Neer II/III, isolated injury, skeletal maturity, speaking French or English, available for follow-up (FU), and ability to fill questionnaires. Exclusion criteria: Pre-existing pathology to the limb, patient-refusing or too ill to undergo surgery, patient needing another type of treatment (nail, arthroplasty), axillary nerve impairment, open fracture. After consent, patients were randomized to one of the two treatments using the dark envelope method. Pre-injury status was documented by questionnaires (SF12, Q-DASH, Constant score). Range of motion was assessed. Patients were followed at two weeks, six weeks, 3-6-12-18-24 months. Power calculation was done with primary outcome: Q-DASH. A total of 92 patients were randomised in the study and 83 patients were followed for a minimum of 12 months. The mean age was 62 y.o. (+- 14 y.) and 77% were females. There was an equivalent number of Neer II and III, 53% and 47% respectively. Mean FU was of 26 months. Forty-four patients were randomized to the DS and 39 to the DP approach. Groups were equivalent in terms of age, gender, BMI, severity of fracture and pre-injury scores. All clinical outcome measures were in favor of the deltopectoral approach. Primary outcome measure, Q-DASH, was better statistically and clinically in the DP group (12 vs 26, p=0,003). Patients with DP had less pain and better quality of life scores than with DS (VAS 1/10 vs 2/10 p=0,019 and SF12M 56 vs 51, p=0,049, respectively). Constant-Murley score was higher in the DP group (73 vs 60, p=0,014). However, active external rotation was better with the DS approach (45° vs 35°). There were more complications in DS patients, with four screw cut-outs vs zero, four avascular necrosis vs one, and five reoperations vs two.
Introduction. The vast majority of intertrochanteric fractures treated with cephalomedullary nails (CMN) will heal. Occasionally even though bony union occurs excessive lag screw sliding can cause persistent pain and soft tissue irritation and return to surgery for hardware removal. The purpose of this study was to evaluate if fracture stability, lag screw tip-apex distance (TAD), and quality of reduction have any impact excessive lag screw sliding and potential cutout. Methods. As part of our level one trauma center's institutional hip fracture registry, a retrospective analysis identified 199 intertrochanteric fractures fixed with CMN between 2009 and 2015 with follow up to union or a minimum of three months. The mean follow-up was 22 months (3 to 94 months). Mean patient age was 75 years (50 to 97 years) and 72% were women. Postoperative radiographs were used to measure the TAD, quality of reduction, neck-shaft angle (NSA), and lateral lag screw prominence. Follow-up radiographs were reviewed to assess fracture union, translation, and progression of lateral lag screw prominence. Complications and reoperations were recorded. Results. The average lag screw sliding was 5±5 mm. Excessive lag screw sliding (defined as > 10 mm; one standard deviation above the mean) was present in 12% of patients. Lag screw sliding was more common in unstable fracture patterns (21% vs. 5%, p<0.01) and patients with
We undertook a randomised prospective follow-up study of changes in peri-prosthetic bone mineral density (BMD) after hip resurfacing and compared them with the results after total hip replacement. A total of 59 patients were allocated to receive a hip resurfacing (n = 29) or an uncemented distally fixed total hip replacement (n = 30). The BMD was prospectively determined in four separate regions of interest of the femoral neck and in the
Intraoperative fractures during primary total hip arthroplasty (THA) can occur on either the acetabular or the femoral side. A range of risk factors including smaller incision surgery, uncemented components, prior surgery, female sex, osteoporosis, and inflammatory arthritis have been identified. Acetabular fractures are rare but when they do occur often are underrecognised. It is not uncommon for intraoperative acetabular fractures to be discovered only postoperatively. Intraoperative acetabular fractures are associated with cementless implants and a number of identified anatomic risk factors. Factors related to surgical technique, including excessive under-reaming, excessive medialization with aggressive reaming, and implant designs such as an elliptical cup design are associated with higher risk. Treatment of acetabular fractures is dependent on whether they are diagnosed intraoperatively or postoperatively. When discovered intraoperatively, supplemental fixation should be added in the form of additional screw fixation, placing a pelvic plate, or using an acetabular reconstruction cage and morselised allografts. Acetabular reamings, obtained during preparation of the acetabulum, can be used for local bone graft. The goal should be stability of both the fracture and acetabular cup. Postoperatively, weight bearing and mobilization protocols may require modification, with many surgeons choosing a period of toe-touch weight-bearing in such cases. Acetabular fractures found postoperatively require the surgeon to make a judgement on the relative stability of the implant and the fracture to determine if immediate revision surgery or protected weight-bearing alone is appropriate. On the femoral side intraoperative fractures can occur around the greater trochanter, the
Introduction. Although total hip arthroplasty is a very successful operation, complications such as: dislocation, aseptic loosening, and periprosthetic fracture do occur. These aspects have been studied in large populations for traditional stem designs, but not for more recent short stems. The design rationale of short stems is to preserve bone stock, without compromising stability. However, due to their smaller bone contact area, high peak stresses and areas of stress shielding could appear in the proximal femur, especially in the presence of atypical bone geometries. In order to evaluate this aspect, we quantified the stress distribution in atypical proximal femurs implanted with a commercially available
Introduction. One of the objectives of total hip arthroplasty is to restore femoral and acetabular combined anteversion. It is desirable to reproduce both femoral and acetabular antevesions to maximize the acetabular cup fixation coverage and hip joint stability. Studies investigated the resultant of implanted femoral stem anteversion in western populations showed that the implanted femoral stems had only a small portion can meet the desirable femoral anteversion angle. 1. , and anteversion angle increases after the implantation of an anatomical femoral stem with anteverted stem neck comparing to anatomical femoral neck. 2. The purpose of this study was to anatomically measure the anteversion angular difference between metaphyseal long axis and femoral neck in normal Chinese population. The metaphyseal long axis represents the coronal fixation plane of modern cementless medial-lateral cortical fitting taper stem. This angular difference or torsion Δ angle provides the estimation of how much the neck antevertion angle of femoral stem would be needed to match for desirable anatomical femoral neck version. Methods. 140 (77 male and 63 female) anonymous normal adult Chinese CT data with average age of 54.6 (male 54.6, female 54.5, P=0.95) were segmented and reconstructed to 3D models in Trauson Orthopeadic Modeling and Analytics (TOMA) program. Femoral head center, femoral neck axis and center point of diaphyseal canal 100mm bellow
Femoral components in total hip replacements fail in well-known ways. There is vertical sink, posterior rotation and pivot, either distal or mid-stem. In order to sink, the stem moves into valgus and then slides down the inside of the
Introduction. Negative remodelling of the femoral cortex in the form of
A longitudinal study was done assessing the latest radiographs available in a series of collarless Corail uncemented stems which have reported survival rates of 95% at 20 years. Parameters scored included the degree of “Ghosting” or delamination, the Gruen, the stem fit in the femoral canal and the degree of
Negative remodelling of the femoral cortex in the form of
Conventional hip arthroplasty femoral stems bypass the femoral neck for fixation. The femoral neck and proximal femur has a complex anatomy and interosseous structure to facilitate transfer of mechanical load in axial, compression bending and torsion mechanisms. von Mises analysis suggests a short stem, fixed in the femoral neck would maintain proximal femoral biomechanics, achieve physiological load transfer to the femoral neck and preserve bone stock and function. The strong
Abstract. Skeletal kinematics are traditionally measured by motion analysis methods such as optical motion capture (OMC). While easy to carry out and clinically relevant for certain applications, it is not suitable for analysing the ankle joint due to its anatomical complexity. A greater understanding of the function of healthy ankle joints could lead to an improvement in the success of ankle-replacement surgeries. Biplane video X-ray (BVX) is a technique that allows direct measurement of individual bones using highspeed, dynamic X-Rays. Objective. To develop a protocol to quantify in-vivo foot and ankle kinematics using a bespoke High-speed Dynamic Biplane X-ray system combined with OMC. Methods. Two healthy volunteers performed five level walks and step-down trials while simultaneous capturing BVX and synchronised OMC. participants undertook MR imaging (Magnetom 3T Prisma, Siemens) which was manually segmented into 3D bone models (Simpleware Scan IP, Synopsis). Bone position and orientation for the Talus, Tibia and
Interestingly, recent studies have shown promising outcomes in elderly. To the best of our knowledge there are no reports available assessing sequential bone remodelling around DCPD (dicalcium phosphate dehydrate) coated short metaphyseal loading stem using serial radiography. Hence we report the unique patterns of bone remodelling in patients 70 years and older and whether these patterns were different from those seen in younger patients. A total of 41 consecutive primary hip arthroplasties were performed in patients with averaged age of 78.3 years using short stem. The presence and patterns of radiolucent lines, radio-opaque lines,
Aims. The aim of this study was to evaluate the clinical and radiological
outcome of using an anatomical short-stem shoulder prosthesis to
treat primary osteoarthritis of the glenohumeral joint. Patients and Methods. A total of 66 patients (67 shoulders) with a mean age of 76 years
(63 to 92) were available for clinical and radiological follow-up
at two different timepoints (T1, mean 2.6 years, . sd. 0.5;
T2, mean 5.3 years,. sd. 0.7). Postoperative radiographs
were analyzed for stem angle, cortical contact, and filling ratio
of the stem. Follow-up radiographs were analyzed for timing and
location of bone adaptation (cortical bone narrowing, osteopenia,
spot welds, and condensation lines). The bone adaptation was classified
as low (between zero and three features of bone remodelling around
the humeral stem) or high (four or more features). Results. The mean Constant score improved significantly from 28.5 (. sd. 11.6)
preoperatively to 75.5 (. sd. 8.5) at T1 (p < 0.001) and
remained stable over time (T2: 76.6, . sd. 10.2). No stem
loosening was seen. High bone adaptation was present in 42% of shoulders
at T1, with a slight decrease to 37% at T2. Cortical bone narrowing
and osteopenia in the region of the
Abstract. Objective. To compare the periprosthetic fracture mechanics between a collared and collarless fully coated cementless femoral stem in a composite femur. Methods. Two groups of six composite femurs (‘Osteoporotic femur’, SawBones, WA USA) were implanted with either a collared (collared group) or collarless (collarless group) cementless femoral stem which was otherwise identical by a single experienced surgeon. Periprosthetic fractures of the femur were simulated using a previously published technique. High speed video recording was used to identify fracture mechanism. Fracture torque and angular displacement were measured and rotational work and system stiffness were estimated for each trial. Results were compared between collared and collarless group and the comparison was evaluated against previously published work using fresh frozen femurs and the same protocol. Results. In composite femur testing median fracture torque (IQR) was greater with a collared versus collarless implant (48.41 [42.60 to 50.27] Nm versus 45.12 [39.13 to 48.09] Nm, p= 0.4). Median rotational displacement (IQR) was less with a collared versus collarless implant (0.29 [0.27 to 0.31] radians versus 0.33 [0.32 to 0.34] radians, p= 0.07). Estimated rotary work was similar between groups (5.76 [4.92 to 6.64] J versus 5.21 [4.25 to 6.04] J, p= 0.4). Torsional stiffness was greater with a collared versus collarless implant (158.36 [152.61, 163.54] Nm per radian versus 138.79 [122.53, 140.59] Nm per radian, p= 0.5). Collarless stems were seen to move independently of the femur and fracture patterns originated at the
The Failed Femoral Neck Fracture. For the young patient: Attempt to preserve patient's own femoral head. Clinical results reasonably good even if there are patches of avascular necrosis. Preferred methods of salvage: valgus-producing intertrochanteric femoral osteotomy: puts the nonunion under compression. Other treatment option: Meyer's vascularised pedicle graft. For the older patient: Most reliable treatment is prosthetic replacement. Decision to use hemiarthroplasty (such as bipolar) or THA based on quality of articular cartilage, perceived risk of instability problem. In most patients THA provides higher likelihood of excellent pain relief. Specific technical issues: (1) hardware removal: usually remove after hip has first been dislocated (to reduce risk of femur fracture); (2) Hip stability: consider methods to reduce dislocation risk: larger diameter heads/dual mobility/anteriorly-based approaches; (3) Acetabular bone quality: poor because it is not sclerotic from previous arthritis; caution when impacting a pressfit cup; low threshold to augment fixation with screws; don't overdo reaming; just expose the bleeding subchondral bone. A reasonable alternative is a cemented cup. The Failed Intertrochanteric Hip Fracture. For the young patient: Attempt to salvage hip joint with nonunion takedown, autogenous bone grafting and internal fixation. For the older patient: Decision to preserve patient's own hip with internal fixation versus salvage with hip arthroplasty should be individualised based on patient circumstances, fracture pattern, bone quality. THA is an effective salvage procedure for this problem in older patients. If prosthetic replacement is chosen special considerations include:. THA vs. hemiarthroplasty: hemiarthroplasty better stability; THA more reliable pain relief. Removal of hardware: be prepared to remove broken screws in intramedullary canal. Management of bone loss: bone loss to level of lesser trochanter common. Often requires a
Aims. Modular dual mobility (DM) prostheses in which a cobalt-chromium liner is inserted into a titanium acetabular shell (vs a monoblock acetabular component) have the advantage of allowing supplementary screw fixation, but the potential for corrosion between the liner and acetabulum has raised concerns. While DM prostheses have shown improved stability in patients deemed ‘high-risk’ for dislocation undergoing total hip arthroplasty (THA), their performance in young, active patients has not been reported. This study’s purpose was to assess clinical outcomes, metal ion levels, and periprosthetic femoral bone mineral density (BMD) in young, active patients receiving a modular DM acetabulum and recently introduced titanium, proximally coated, tapered femoral stem design. Patients and Methods. This was a prospective study of patients between 18 and 65 years of age, with a body mass index (BMI) < 35 kg/m. 2. and University of California at Los Angeles (UCLA) activity score > 6, who received a modular cobalt-chromium acetabular liner, highly crosslinked polyethylene mobile bearing, and cementless titanium femoral stem for their primary THA. Patients with a history of renal disease and metal hardware elsewhere in the body were excluded. A total of 43 patients (30 male, 13 female; mean age 52.6 years (. sd. 6.5)) were enrolled. All patients had a minimum of two years’ clinical follow-up. Patient-reported outcome measures, whole blood metal ion levels (ug/l), and periprosthetic femoral BMD were measured at baseline, as well as at one and two years postoperatively. Power analysis indicated 40 patients necessary to demonstrate a five-fold increase in cobalt levels from baseline (alpha = 0.05, beta = 0.80). A mixed model with repeated measures was used for statistical analysis. Results. Mean Harris Hip Scores improved from 54.1 (. sd. 20.5) to 91.2 (. sd. 10.8) at two years postoperatively (p < 0.001). All patients had radiologically well-fixed components, no patients experienced any instability, and no patients required any further intervention. Mean cobalt levels increased from 0.065 ug/l (. sd. 0.03) preoperatively to 0.30 ug/l (. sd. 0.51) at one year postoperatively (p = 0.01) but decreased at two years postoperatively to 0.16 ug/l (. sd. 0.23; p = 0.2). Four patients (9.3%) had a cobalt level outside the reference range (0.03 ug/l to 0.29 ug/l) at two years postoperatively, with values from 0.32 ug/l to 0.94 ug/l. The mean femoral BMD ratio was maintained in Gruen zones 2 to 7 at both one and two years postoperatively using this stem design. At two years postoperatively, mean BMD in the medial
INTRODUCTION. The increasing incidence of periprosthetic femoral fractures (PFF) after total hip arthroplasty presents growing concerns due to challenges in treatment and increased mortality. PFF are often observed when the prosthesis is implanted in varus, especially with blade-type stems. To help elucidate its impact on the PFF risk, the specific research question is: What is the effect of misalignment of a blade-type stem (resulting in down-sized prosthesis) on 1)the distribution and magnitude of cortical stresses and 2)implant-bone micromotion. METHOD. We developed two finite element models consisting of an average female femur implanted within a generic blade-type stem prosthesis, (i)in neutral alignment, and (ii)oriented in 5° of varus, coupled with corresponding down-sizing of the prosthesis. Each model consisted of 1.1million elements, while the average mesh length at the implant-bone interface was 0.4mm. Elastic moduli of 15GPa(cortex), 150MPa(trabecular bone), and 121GPa(implant), and Poisson's ratio of 0.3 were assumed. The distal end was fixed and the interface was defined as a surface-to-surface contact with friction coefficients (dynamic 0.3; static 0.4). Walking and stair-climbing were simulated by loading the joint contact and muscle forces after scaling to the subjects’ body weight. The peak von Mises stress and the average stress within the surface having 1cm diameter and the center at where the peak stress occurred at each contacting area, the interfacial micromotion along medial, lateral side were analyzed. For statistical analysis, two-tailed t-test was performed between the neutral and varus cases over four loading cycles with significance level of p<0.05. RESULTS. Neutral alignment led to three areas of cortical/implant contact with focal load transfer via those areas, whereas varus placement limited to two areas (Figure 1). In both simulations, the greatest stress was observed at the proximal medial contact. With varus, average and peak stresses increased by 39% and 65% during walking and 28% and 35% during stair-climbing, respectively (Table 1). Micromotion was greatest over the proximal third of the interface, especially along lateral side (Figure 2). The 90. th. percentile values with the varus exceeded the neutral by 35% with walking and 28% with stair-climbing over the lateral interface. DISCUSSION. The proximal medial location of the greatest stress correlates well with clinical observations in PFF involving a posteromedial
The triple taper polished cemented stem (C-stem, DePuy) was developed to promote
Intra-operative fractures of the femur are on the rise mainly due to the increased use of cementless implants and the desire to get a tight press fit. The prevalence has been reported to be between 1–5% in cementless THAs. The key to preventing these fractures is to identify patients at high risk and careful surgical technique. Surgical risk factors include the use of cementless devices, revision hip surgery, the use of flat tapered wedges and MIS surgery. Patient factors that increased risk include increasing age, female gender, osteopenia and rheumatoid arthritis. These risk factors tend to be additive and certainly when more than one is present extra caution needs to be taken. Surgical technique is critical to avoid these intra-operative fractures. Fractures can occur during exposure and dislocation, during implant removal (in revision THA), during canal preparation and most commonly during stem insertion. In both primary, and especially in revision, THA be wary of the stiff hip in association with osteopenia or osteolysis. These patients require a very gentle dislocation. If this cannot be achieved, then alteration of the standard approach and dislocation may be needed. Examples of these include protrusion with an osteopenic femur and revision THA with a very stiff hip with lysis in the femur. Lastly, in cases with retained hardware, dislocate prior to removing plates and screws. After dislocation, the next challenge is gentle preparation of the femoral canal. A reasonable exposure is required to access the femoral canal safely. MIS procedures do not offer good access to femoral canal and this probably results in increased risk of fracture during broaching or implant insertion. When broaching, stop when broach will not advance further. When inserting a tapered wedge stem, be worried if stem goes further in than broach. In revision surgery, when taking the stem out from above, make sure the area of the greater trochanter does not overhang the canal. A high speed burr can clear the shoulder for easier access for removal. In revision THA with an ETO, place a cerclage wire prior to reaming and retighten prior to stem insertion. Even with careful surgical technique intra-operative femoral fractures will still occur. When inserting the stem, a sudden change in resistance is highly suggestive of fracture. Wide exposure of the entire proximal femur is necessary to confirm the diagnosis. The distal extent of the fracture must be seen. Only on occasion is an intra-operative radiograph needed. Management is directed to ensuring component stability and good fracture fixation. In primary total hip arthroplasty,
Background : A composite femoral stem was introduced with a structural stiffness similar to that of the native femur to promote proximal load transfer. This consisted of a cobalt-chromium alloy core surrounded by an injection-moulded layer of polyaryletherketone covered with a porous titanium mesh. Material and Methods: 31 consecutive primary total hip replacement stems were implanted in 26 patients with an average age of 37 years (range 17–57) using the Epoch stem (Zimmer, Warsaw, IN) as part of a prospective multi-centre trial. A cementless Harris-Galante I acetabular component with a 28mm polyethylene insert (Zimmer) was used in 29 cases, a Plasmacup with 28mm polyethylene insert (Aesculap, Tuttlingen, Germany) in 1 case and a bipolar head in 1 case. Annual follow-up with Harris Hip Scores and radiographic evaluation was performed for a mean of 10.1 years. Results : Harris Hip Scores improved from a mean of 52 points preoperatively to 90 at the time of last follow-up. Radiographs showed no stem migration or loosening. 4 cases with polyethylene wear showed trochanteric osteolysis. Specific radiographic features noted were a sclerotic halo in Gruen zones 1 in 8 cases,
Objective. The purpose of this study was to compare the proximal femoral morphology between normal Chinese and Caucasian populations by 3D analysis derived from CT data. Materials and Methods. 141 anonymous Chinese femoral CT scans (71 male and 70 female) with mean age of 60.1years (range 20–93) and 508 anonymous Caucasian left femoral CT scans (with mean age of 64.8years (range 20–93). The CT scans were segmented and converted to virtual bones using custom CT analytical software. (SOMA™ V.4.0) Femoral Head Offset (FHO) and Femoral Head Position (FHP) were measured from head center to proximal canal central axis and to
The aim of this study was to investigate the
relationship between the geometry of the proximal femur and the incidence
of intra-operative fracture during uncemented total hip arthroplasty
(THA). We studied the pre-operative CT scans of 100 patients undergoing
THA with an uncemented femoral component. We measured the anteroposterior
and mediolateral dimensions at the level of division of the femoral
neck to calculate the aspect ratio of the femur. Wide variations
in the shape of the femur were observed, from round, to very narrow
elliptic. The femurs of women were narrower than those of men (p
<
0.0001) and small femurs were also narrower than large ones.
Patients with an intra-operative fracture of the
Purpose: More and more younger patients needs primary hip replacement. Specially for these patients the so called
Introduction. The purpose of the study was to assess the clinical outcomes of an algorithm for soft tissue femoral release in anterior approach (AA) total hip arthroplasty (THA). Specifically, the following were assessed in this series of patients utilizing a standardized soft tissue release sequence: 1) clinical outcomes with the Harris Hip Score (HHS); 2) re-operation rates; 3) component survivorship; and 4) complications. Methods. We retrospectively analyzed a prospectively maintained database of patients who underwent AA THA from 2014 to 2017. A total of 1000 patients were included, with minimum follow up of 2 years (range 2–5 years). The mean age was 65 years (range, 22–89), 48% were males, and the mean Body Mass Index was 34 (range, 20–52). Descriptive statistics were performed for most endpoints except for component survivorship, which was assessed with Kaplan-Meier analysis. Result. There was 95% follow-up (54 patients lost to follow-up). The HHS improved from mean 56 preoperatively (range, 34–78) to mean 88 post-operatively (range, 65–100) (p<0.01). There were three complications: one superficial wound dehiscence which resolved with outpatient secondary operative wound closure; one
Aims. Modular or custom-made femoral components have been preferred
for total hip arthroplasty (THA) in patients with a history of Perthes’
disease because of the distortion in the anatomy of the proximal
femur. However, it has not been established whether a monobloc cementless
stem will fit the distorted proximal femur or whether the results
of the procedure are satisfactory in this group of patients. Patients and Methods. We reviewed 68 consecutive patients who had undergone THA for
childhood Perthes’ disease between June 2003 and December 2008.
There were 35 men and 33 women with a mean age of 48 years (16 to
73) at the time of index arthroplasty. Their mean body mass index
was 24.4 (18.3 to 32.9). Of the 68 hips, 32 were classified as Stulberg
class III and 36 as class IV. The mean pre-operative shortening
of the affected leg was 17.2 mm (5 to 34). The minimum follow-up
was five years (mean 8.5 years; 5.2 to 10). Results. An intra-operative