Timing Expression of miR203a-3p during OA Disease: Preliminary In Vitro Evidence.

Osteoarthritis (OA) is a degenerative bone disease that involves the microenvironment and macroenvironment of joints. Progressive joint tissue degradation and loss of extracellular matrix elements, together with different grades of inflammation, are important hallmarks of OA disease. Therefore, the identification of specific biomarkers to distinguish the stages of disease becomes a primary necessity in clinical practice. To this aim, we investigated the role of miR203a-3p in OA progression starting from the evidence obtained by osteoblasts isolated from joint tissues of OA patients classified according to different Kellgren and Lawrence (KL) grading (KL ≤ 3 and KL > 3) and hMSCs treated with IL-1ß. Through qRT-PCR analysis, it was found that osteoblasts (OBs) derived from the KL ≤ 3 group expressed high levels of miR203a-3p and low levels of ILs compared with those of OBs derived from the KL > 3 group. The stimulation with IL-1ß improved the expression of miR203a-3p and the methylation of the IL-6 promoter gene, favoring an increase in relative protein expression. The gain and loss of function studies showed that the transfection with miR203a-3p inhibitor alone or in co-treatments with IL-1ß was able to induce the expression of CX-43 and SP-1 and to modulate the expression of TAZ, in OBs derived from OA patients with KL ≤ 3 compared with KL > 3. These events, confirmed also by qRT-PCR analysis, Western blot, and ELISA assay performed on hMSCs stimulated with IL-1ß, supported our hypothesis about the role of miR203a-3p in OA progression. The results suggested that during the early stage, miR203a-3p displayed a protective role reducing the inflammatory effects on CX-43, SP-1, and TAZ. During the OA progression the downregulation of miR203a-3p and consequently the upregulation of CX-43/SP-1 and TAZ expression improved the inflammatory response and the reorganization of the cytoskeleton. This role led to the subsequent stage of the disease, where the aberrant inflammatory and fibrotic responses determined the destruction of the joint.

How miR-31-5p and miR-33a-5p Regulates SP1/CX43 Expression in Osteoarthritis Disease: Preliminary Insights.

Osteoarthritis (OA) is a degenerative bone disease that involved micro and macro-environment of joints. To date, there are no radical curative treatments for OA and novel therapies are mandatory. Recent evidence suggests the role of miRNAs in OA progression. In our previous studies, we demonstrated the role of miR-31-5p and miR-33a families in different bone regeneration signaling. Here, we investigated the role of miR-31-5p and miR-33a-5p in OA progression. A different expression of miR-31-5p and miR-33a-5p into osteoblasts and chondrocytes isolated from joint tissues of OA patients classified in based on different Kellgren and Lawrence (KL) grading was highlighted; and through a bioinformatic approach the common miRNAs target Specificity proteins (Sp1) were identified. Sp1 regulates the expression of gap junction protein Connexin43 (Cx43), which in OA drives the modification of i) osteoblasts and chondrocytes genes expression, ii) joint inflammation cytokines releases and iii) cell functions. Concerning this, thanks to gain and loss of function studies, the possible role of Sp1 as a modulator of CX43 expression through miR-31-5p and miR-33a-5p action was also evaluated. Finally, we hypothesize that both miRNAs cooperate to modulate the expression of SP1 in osteoblasts and chondrocytes and interfering, consequently, with CX43 expression, and they might be further investigated as new possible biomarkers for OA.

Pushing Ceramic-on-Ceramic in the most extreme wear conditions: A hip simulator study.

BACKGROUND: Hip revision surgery for fractured ceramic components may represent the worst-case wear scenario due to the high risks of recurrent dislocations, instability, and third body wear. The ideal bearing choice for the new prosthetic articulation is still subject of debate, while alumina matrix composite (AMC) articulations offer theoretical superior performances; the present work was designed to test the wear behaviour of ceramic on ceramic articulations (liner and head) in a worst-case scenario by adding ceramic third-body particles to the test lubricant with combined walking and subluxation cycles in a hip joint simulator. Therefore, we performed an in vitro study aiming to assess how does AMC articulation perform with 1) third-body particles added to the test environment and 2) under subluxation stresses. HYPOTHESIS: We hypothesised that AMC articulations offer superior performances in such worst conditions. MATERIALS AND METHODS: A hip simulator test was designed to analyse how AMC articulation performs with third-body particles added to the test environment and under subluxation stresses. Two different load patterns including level walking and subluxation of the ceramic liner were applied. The test fluid lubricant was contaminated by adding coarse ceramic particles during the first 2 million cycles and fine ceramic particles from 2 to 4 million cycles. Group 1 consisted of an alumina matrix composite articulation (liner and head); group 2 consisted of an alumina liner and an alumina matrix composite head. A control group consisting of an alumina ceramic liner articulated against an alumina matrix composite head was provided and only axially loaded. The liners of groups 1 and 2 were tested at an in vivo angle of 45° in the medial lateral plane (inclinationangle), which corresponds to an angle L=30° relative to the ISO standard fixated position used for in vitro testing. All mass measurements were performed using a high precision balance (Sartorius BP211D). During each examination, images on dedicated location of the bearing surfaces were taken using a digital microscope. RESULTS: Mean cumulative wear of 0.09mg per million cycles between 2 and 4 million cycles was detected in group 2, and this value was significantly lower (p=0.016) in comparison with the average value in group 1 (0.21mg per million cycle). This result can be explained in light of a possible transformation phase of zirconia in AMC liners, probably due to excessive stress during subluxation cycles. However, wear levels observed are close to the gravimetric measurement detection limit of the Sartorious Balance (about 0.1-0.2mg); therefore, wear can be considered negligible in all groups. CONCLUSION: Our results confirm that AMC couplings perform very well even in the worst-case wear scenario. Since AMC articulations revealed 25% lower cumulative wear respect to AMC on cross linked polyethylene in same simulator setup, AMC articulations should be considered the bearing of choice in revision surgery in light of the high risk of recurrent dislocations, instability, and third body wear. LEVEL OF EVIDENCE: III, prospective case-control study, in vitro.

The role of synovial fluid analysis in the detection of periprosthetic hip and knee infections: a systematic review and meta-analysis.

INTRODUCTION: This study tried to ascertain (1) the accuracy of synovial fluid white blood cell count and polymorphonucleate percentage in the diagnosis of periprosthetic hip and knee infections, (2) which test yielded superior test performance, and (3) the influence on diagnostic accuracy of study characteristics such as patient number, study design, study level, anatomic site, and threshold value. METHODS: A systematic search was conducted including papers assessing more effective cutoffs for synovial fluid tests, having comparative design, evaluating an exclusive cohort of hip or knee prostheses, including a clear definition of infected cases, and reporting sufficient data for the calculation of true-positive, false-positive, false-negative, and true-negative. RESULTS: A total of 375 articles were collected and, given the inclusion criteria, ten manuscripts were included. These studies assessed 1155 hip prostheses (276 infected cases) and 1235 knee prostheses (401 infected cases). The specificity of synovial fluid white blood cell count was significantly increased by using the threshold value ≥ 3000 cell/µL (p = 0.006); the sensitivity of polymorphonucleate percentage was significantly higher in detecting knee infections (p = 0.034). DISCUSSION: Both tests had a high specificity and sensitivity in detecting periprosthetic joint infections, and no clear superiority of one over the other existed. Furthermore, cutoff and anatomic site significantly influenced synovial fluid white blood cell count and polymorphonucleate percentage, respectively. CONCLUSION: Synovial fluid analysis is adequate in differentiating patients with periprosthetic hip and knee infections. Our data confirms international guidelines suggesting the use of 3000 cell/µL as cutoff threshold for synovial fluid white blood cell count. Since an anatomic site effect has been demonstrated, the goal of future studies will be to identify different cutoffs for hip and knee prostheses.

Sciatic Nerve Palsy following Total Hip Replacement: Are Patients Personal Characteristics More Important than Limb Lengthening? A Systematic Review.

Sciatic nerve palsies are rare but potentially devastating complications, accounting for more than 90% of neurologic injuries following total hip replacement. A systematic literature screening was carried out searching papers evaluating an exclusive population of postarthroplasty sciatic nerve palsies to ascertain (1) the influence of limb lengthening itself on sciatic nerve palsy, (2) the most important risk factors, (3) the long-term prognosis, and (4) the outcomes of different treatments. Fourteen manuscripts were finally included. The wide prevalence of retrospective case series decreased the global methodological quality of the retrieved papers. A hazardous lengthening threshold cannot be surely identified. Developmental dysplasia of the hip and previous hip surgeries are the most frequently recognized risk factors. Rate of full nerve function restoration approximates two-thirds of the cases, independently of the extent of initial neural damage. Poor evidences are available about the best treatment strategy. Well-structured multicentric prospective comparative studies are needed to substantiate or contrast the finding of this review. Anyway, since the onset of palsies is probably due to a combination of individual factors, risk of nerve damage and potential for nerve recovery should be evaluated on an individual basis.

Effect of different postoperative flexion regimes on the outcomes of total knee arthroplasty: randomized controlled trial.

PURPOSE: A consistent limb position strategy could be an attractive and easier alternative to reduce blood loss and increase range of motion following total knee arthroplasty. The aim of this study was to understand the proper amount of flexion required to improve functional outcomes with limited patients' discomfort. METHODS: Eighty-five patients undergoing total knee arthroplasty were randomly assigned to receive mild (30° of knee flexion) or high-flexion protocol (70° of knee flexion), 48 h after surgery. The same daily rehabilitation scheme was followed. Total blood loss, hidden blood loss, haemoglobin and haematocrit levels, fixed flexion deformity, range of motion and limb circumference at the superior patellar pole were evaluated preoperatively and 7 days after surgery. RESULTS: Demographics, blood parameters and preoperative range of motion did not show any significant difference between the two groups. No complications were recorded in both groups. High-flexion group had greater rate of dropout due to excessive patients' discomfort. A significantly lower Hb at day 1 was found in the high-flexion group. No differences were recorded regarding the remaining parameters. CONCLUSION: No significant differences were found between the high-flexion and mild-flexion protocols; however, mild-flexion protocol was better tolerated by patients. We therefore recommend a 30° flexion protocol to be routinely used 48 h postoperatively after total knee arthroplasty. This is an easy strategy to improve functional outcomes, which is a fundamental issue considering the steady increase in knee prostheses utilization. LEVEL OF EVIDENCE: Randomized controlled trial, Level II.

Outcomes of total hip replacement in limbs affected by poliomyelitis.

INTRODUCTION: The outcomes of total hip replacement in patients suffering from residual poliomyelitis are poorly covered in the literature. In this retrospective study we posed the question of whether total hip replacement performed for degenerative hip diseases in limbs with residual poliomyelitis could determine satisfactory mid-term clinical and radiographic results, with a reasonable complication rate. METHODS: A retrospective study was carried out to assess the results of 14 total hip replacements performed on 14 patients with residual poliomyelitis on the involved limb from June 1999 to September 2011. Average age at the time of surgery was 51 years (range 26-66 years). Mean duration of follow-up was 92 months (range 52-156 months). Surgery was performed through a direct lateral approach on all hips. All but one were cementless implants. RESULTS: 2 implants failed, 1 due to traumatic acetabular fracture 6 days after surgery, and 1 due to aseptic cup loosening 13 years after surgery. Surgery was uneventful in all patients except 1 (7%), who experienced a transient sensory sciatic nerve palsy. At the latest follow up Harris Hip Score was 83.3 (range 72-91) with a marked improvement when compared to preoperative score (average 52, range 32-78). No dislocations had occurred. CONCLUSIONS: Total hip replacement can be considered a feasible option for hip osteoarthritis in patients with limbs affected by residual poliomyelitis. Longer follow-up studies are needed to assess the effectiveness of unconstrained total hip replacement in polio patients.

Anterior minimally invasive subcapital osteotomy without hip dislocation for slipped capital femoral epiphysis.

PURPOSE: A minimally invasive anterior approach appears to be an attractive alternative to achieve capital realignment without violating femoral head vascular supply and avoiding hip dislocation in slipped capital femoral epiphysis. The aim of this study was to detail the technical steps of subcapital realignment through a minimally invasive anterior approach and to report the preliminary results of this procedure in a prospective cohort of patients with stable slips. METHODS: Nine patients underwent subcapital cuneiform wedge resection through a minimally invasive anterior approach without hip dislocation for moderate or severe stable slips between April 2012 and April 2013. Prophylactic stabilization of the contralateral hip was performed in all cases. A minimum 18 months follow-up was available. Clinical course was assessed using the Harris hip score and the hip range of motion. The degree of slippage as proposed by Southwick, the lateral α angle and the epiphyseal-metaphyseal distance allowed radiographic assessment. RESULTS: No patients were lost during follow-up, which was on average 28 months. No intraoperative complications occurred; one postoperative transient apraxia of the femoral cutaneous nerve, which completely recovered in six months, was recorded. Southwick angle, lateral α angle and epiphyseal-metaphyseal distance all improved substantially postoperatively. No cases of avascular necrosis were detected. CONCLUSION: Subcapital cuneiform wedge resection through a minimally invasive anterior approach without hip dislocation can be an easier alternative to restore proximal femoral anatomy in moderate to severe stable slips. Prospective case control studies are required to confirm these preliminary results.

Post-operative limb position can influence blood loss and range of motion after total knee arthroplasty: a systematic review.

PURPOSE: A consistent post-operative limb positioning regime could be an attractive, simple and cost-effective alternative to improve patient's outcomes after total knee arthroplasty (TKA). The aim of this study was to perform a systematic review of the available literature in order to understand whether a consistent post-operative limb positioning regime could affect blood loss and range of motion (ROM) after TKA. METHODS: A search was performed using the keywords "total knee replacement/knee prosthesis" in combination with "post-operative management", "blood loss", "range of motion", "leg position", "flexion", "extension" and "splinting" regardless of the year of publication. The scientific databases have been accessed in order to identify papers dealing with post-operative limb positioning regimes after TKA. RESULTS: Seven articles matching the inclusion criteria were selected. Blood loss and ROM were both investigated in all but one paper, in which only blood loss was evaluated. There were six randomized controlled trials and one prospective comparative study. A 48-72 h post-operative knee flexion protocol seems to be effective in reducing blood loss and increasing ROM following TKA. We did also find no benefit in using extension splints in the immediate post-operative period. CONCLUSIONS: Based on the studies undertaken to date, a 48-72 h post-operative knee flexion protocol should be implemented as an easy and inexpensive method of reducing blood loss and increasing ROM following TKA. Shorter flexion regimes failed to influence these parameters.

Fracture of ceramic bearing surfaces following total hip replacement: a systematic review.

Ceramic bearing surfaces are increasingly used for total hip replacement, notwithstanding that concern is still related to ceramic brittleness and its possible mechanical failure. The aim of this systematic review is to answer three questions: (1) Are there risk factors for ceramic component fracture following total hip replacement? (2) Is it possible to perform an early diagnosis of ceramic component failure before catastrophic fracture occurs? (3) Is it possible to draw guidelines for revision surgery after ceramic components failure? A PubMed and Google Scholar search was performed and reference citations from publications identified in the literature search were reviewed. The use of 28 mm short-neck femoral head carries an increased risk of fracture. Acetabular component malposition might increase the risk of ceramic liner fractures. Synovial fluid microanalysis and CT scan are promising in early diagnosis of ceramic head and liner failure. Early revision is suggested in case of component failure; no consensus exists about the better coupling for revision surgery. Ceramic brittleness remains a major concern. Due to the increased number of ceramic on ceramic implants, more revision surgeries and reports on ceramic components failure are expected in the future. An algorithm of diagnosis and treatment for ceramic hip failure is proposed.

Risk factors for ceramic liner fracture after total hip arthroplasty.

The aim of this study was to detect risk factors for ceramic liner fractures. 26 cementless ceramic on ceramic (COC) total hip arthroplasties (THA) revised because of ceramic liner fracture in 24 patients were compared with 49 well-functioning COC THA performed in 49 patients. Demographic parameters, type of ceramic of the liner, size and neck length of the femoral head, cup abduction angle, cup anteversion, femoral off-set, height of the centre of rotation and the incidence of noisy hips during follow-up examination were compared. A greater number of cups placed outside the optimal range of cup anteversion was found in the fracture group (p = 0.03). An audible noise was detected in 21 cases (80.7%) in the fracture group and in 3 cases (6.1%) in the non-fracture group (p = 0.001). A cup anteversion angle out of the optimal range of 15˚+/-10˚ was found to be a risk factor for ceramic liner fracture and the presence of a noisy hip frequently anticipated the failure. In our opinion neck-to-cup impingement with head subluxation and edge loading on the liner rim could have an important role in the onset of noise and subsequent liner failure, and cup malposition contributes to this mechanism of failure.

Outcomes of total hip replacement in patients with slipped capital femoral epiphysis.

BACKGROUND: Total hip replacement has been advocated for the treatment of degenerative hip diseases secondary to slipped capital femoral epiphysis; nonetheless, outcomes of this procedure have not been well established. We reviewed the outcomes of modern total hip replacements in patients who suffered from slipped capital femoral epiphysis. METHODS: A retrospective study was carried out on 32 total hip replacements performed on 28 patients who suffered from slipped capital femoral epiphysis from August 1994 to January 2007. The average age at the time of surgery was 45 years. Clinical evaluation was performed using the Harris Hip Score, radiographic assessment measuring cup and stem orientation, the extent of osteolysis around the implant, and leg length discrepancy. The average follow-up was 98 months (range 25-204 months). RESULTS: Two total hip replacements failed, one for stem aseptic loosening and the other for modular neck failure. The cumulative survival rate at 9 years was 92.8 %. If the end point was revision for implant loosening, the survival rate improved to 96.8 % at 9 years. The only complication recorded was an intraoperative fracture of the lesser trochanter immediately treated with cerclage wire. At the latest follow-up, the Harris Hip Score averaged 86 (range 70-97). Leg length discrepancies greater than 1 cm were present in 18 cases before surgery, and in only 6 cases after surgery. DISCUSSION: We recommend total hip replacement for patients who suffer from slipped capital femoral epiphysis because of the satisfactory survival, low complication rate, and the possibility of restoring leg length.

Patient weight more than body mass index influences total hip arthroplasty long term survival.

The effect of obesity on the long-term survival of total hip arthroplasty remains under discussion. Reviewing meta-analyses of large cohort studies a high body mass index has been correlated with a higher incidence of complications but not univocally with a lower implant survival rate. It has been suggested that body weight rather than body mass index might be a better parameter to evaluate prosthesis outcome. We reviewed 27,571 patients retrospectively with primary arthritis as a preoperative diagnosis. Patients were divided into 4 categories based on their body mass index, or into two groups based on the body weight (<80 kg and =80 kg). Implant survivorship was estimated with use of the Cox proportional hazards model with revision for aseptic loosening as the end point. Results were stratified for sex and implant tribology. When body mass index was used the 10 years implant survival in obese versus non-obese patients was not statistically different (p=0.058), but when body weight was used a statistically different implant survivorship was found for men (p=0.009). Therefore, weight rather than than body mass index influences survival of hip prostheses, and should be used as the discriminant parameter for further studies.

Failure of knee osteotomy in a case of neuropathic arthropathy of the knee.

Neuropathic arthropathy (Charcot's joint) is a degenerative process that affects peripheral or vertebral joints as a consequence of a disturbance in proprioception and pain perception. The knee is one of the most frequently affected joints, but even when the diagnosis is made at an early stage there is no consensus on the best treatment options. An early diagnosis of neurosyphilis was made in a 55-year-old woman presenting a delayed union of an asymptomatic Schatzker type IV fracture of the proximal tibia. A medial opening wedge tibial osteotomy was performed to achieve fracture healing, to correct the medial depression of the articular surface, and possibly to avoid an early arthritis typical of the disease. To our knowledge, a knee osteotomy has never been reported at an early stage of neuropathic arthropathy. Even though the clinical and radiographic evaluation performed at 4 months follow-up showed a good stage of healing of the osteotomy and no typical features of neuropathic joint degeneration, at 8 months follow-up the knee was markedly deranged.

Long-term results of total hip replacement in patients with Legg-Calvé-Perthes disease.

BACKGROUND: Total hip replacement in patients with Legg-Calvé-Perthes disease can be difficult because of the multiplanar deformities of the proximal part of the femur and previous surgery during childhood. The aim of the present study was to assess the long-term outcomes of total hip replacement in patients who had Legg-Calvé-Perthes disease during childhood. METHODS: A retrospective study was carried out to assess the results of thirty-two total hip replacements that had been performed for twenty-seven patients from January 1989 to November 2004. The average age at the time of surgery was 37.8 years. The average duration of follow-up was 124 months (range, fifty-eight to 248 months). All but one of the implants were cementless. RESULTS: There was only one failure in the present study; specifically, the one cemented stem in the study failed two years after surgery. The cumulative survival rate at fifteen years was 96.9% (95% confidence interval, 90.8% to 100.0%). The overall rate of complications was 12.5%, with two permanent sciatic nerve palsies. At the time of the latest follow-up, the average Harris hip score was 87.5 (range, 73 to 96), which was a marked improvement in comparison with the preoperative score (average, 50.1; range, 25 to 75). CONCLUSIONS: Despite the high rate of neurological complications, possibly related to excessive limb lengthening or inadequate soft-tissue release, total hip replacement can be considered a feasible option for patients with Legg-Calvé-Perthes disease. Careful preoperative planning is advisable in order to overcome the technical pitfalls related to the abnormal proximal femoral and acetabular anatomy of these patients.

Modular neck prostheses in DDH patients: 11-year results.

BACKGROUND: Total hip replacement in developmental dysplasia of the hip is a demanding procedure and usually requires dedicated devices and special surgical techniques. Nevertheless, the described techniques have shown variable outcomes. The aim of this study was to assess the 11-year outcomes of an off-the-shelf modular neck prosthesis in dysplastic patients and to evaluate the ability of the modular neck system to adequately restore femoral offset, abductor muscles lever arm and leg length. METHODS: We retrospectively evaluated 61 modular neck prostheses implanted in 47 patients between June 1995 and March 2004. The preoperative diagnosis was developmental dysplasia of the hip in all cases. The clinical outcomes were assessed using the Harris hip score and the Western Ontario and McMaster Universities score. The femoral offset, abductor muscles lever arm, height and medialization of the hip center of rotation, and differences in leg length were evaluated on postoperative radiographs. Prosthesis survival was calculated according to the Kaplan-Meier method considering any reason for revision as failure. The average follow-up was 117.2 months (range 57-162 months). RESULTS: The cumulative survival at 11 years was 97.5%. One prosthesis failed 5 years after surgery because of a ceramic liner fracture due to an inappropriate obstetric maneuver during labour. At the latest follow-up the mean Harris hip score was 74.7 (range 23-91). Leg length discrepancy was avoided in the majority of cases; femoral offset was almost always restored. CONCLUSIONS: The results of this series support the use of modular neck prostheses as an effective alternative in the treatment of developmental dysplasia of the hip. The modularity was very efficient in restoring offset, leg length and maintaining stability with a good mid-long-term follow-up. Unlike other proposed surgical techniques, these good results are achievable by a standard surgical technique and with an off-the-shelf prosthesis.

A reproducible and inexpensive method of measuring hip abductor strength.

The evaluation of hip abductor strength is useful in assessing of the outcome of hip surgery. Hand-held dynamometers are available, but they are less reliable in assessing hip abductor strength than some other muscle groups. We describe a new device designed to measure hip abductor strength, which is practical in a clinical setting. A system of constraints, pads and reference points was devised to make force measurements as little examiner-dependent as possible. Reproducibility was assessed in a controlled setting. The abductor strength of ten healthy young subjects (average age 28 years) was tested twice on each side by two independent examiners. Tests were performed in a supine position, eliminating the influence of gravity and examiner intervention. The results indicated high reproducibility, the maximal measurement uncertainty being within 1 N. Intra-class correlation coefficients ranged from 0.85-0.98 for intra-rater reproducibility, and 0.81-0.96 for inter-rater reporoducibility. The coefficient of variation was lower than 10%. The device described may be suitable for routine clinical assessment of patients after hip surgery.

The influence of the centre of rotation on implant survival using a modular stem hip prosthesis.

The restoration of the hip centre of rotation in an anatomical position is considered to be relevant for total hip prosthesis survival. When the cup is implanted with a high centre of rotation, the lever arm of the abductor muscles is decreased, causing higher joint-reaction forces. Modular stems with varying lengths and geometries can be used to balance soft tissues, and ceramic bearing surfaces can be used to reduce the wear rate. Forty-four hip replacements performed with a high hip centre of rotation were matched with 44 performed with an anatomical centre of rotation. In all cases the preoperative diagnosis was dysplasia of the hip (DDH) and cementless modular neck prostheses with ceramic bearing surfaces were used. At nine years follow-up the mean Harris hip and WOMAC scores were not statistically different. All stems and cups were stable; the femoral offset was no different between the two groups (p = 0.4) as leg-length discrepancy (p = 0.25).

Outcome of hybrid stem fixation in osteoporotic female patients. A minimum five-year follow-up study.

In osteoporotic patients cemented stems are usually used to achieve a good primary stability. However, when patients are obese or active the long-term survival of cemented prostheses is questioned. In these patients, a partially-cemented stem with a hybrid fixation could be advantageous. A hybrid stem was retrospectively evaluated at a minimum follow-up of 60 months (mean, 75 months) in 58 osteoporotic women: seventeen with a body mass index (BMI) >30 (obese), 41 with a BMI between 25 and 29.9 (overweight), and an UCLA score for activity level >6. At the latest follow up, the Harris hip score improved from 33.5 points preoperatively to 81.6 points, and the WOMAC score improved significantly. Three stems (4.9%) had an asymptomatic subsidence of less than 2.5 mm; no stem was revised. These results support the use of partially-cemented stems in heavy or active osteoporotic women.