Subsidence of a Single-Taper Femoral Stem in Primary Total Hip Arthroplasty: Characterization, Associated Factors, and Sequelae.

BACKGROUND: We characterized subsidence of an uncemented single-taper femoral stem in primary total hip arthroplasty (THA), determined factors associated with subsidence, and evaluated the impact of subsidence on outcome. METHODS: This retrospective study included 502 primary THAs performed using a single-taper stem in Dorr type-A and type-B femora between 2014 and 2018. Subsidence was measured based on distance from the greater trochanter to stem shoulder on calibrated X-rays. Demographics, case-specific data, and outcomes were collected. Changes in subsidence and variables associated with subsidence were determined. RESULTS: Stem subsidence was 1.5 ± 2.3 mm, 1.6 ± 2.0 mm, 2.0 ± 2.6 mm, 2.3 ± 2.3 mm, 2.6 ± 2.5 mm, and 2.7 ± 3.0 mm at 6 weeks, 3 months, 6 months, 1 year, 2 years, and ≥3 years from THA, respectively. Subsidence across all patients at final mean follow-up of 24 months (range, 1 to 101 months) was 2.2 ± 2.6 mm. Pairwise comparison demonstrated that subsidence occurred predominantly within the first 6 months. Significant subsidence (≥5 mm) occurred in 17.3% and was associated with a body mass index (BMI) ≥25 (P = .04). Dorr type, age, sex, and American Society of Anesthesiologists class were not associated with subsidence. There were 2 patients (0.4%) who underwent a revision that could be attributed to subsidence. There was no association between subsidence and pain, limp, need for ambulatory aid, or analgesic use. CONCLUSION: In primary THAs performed using a single-taper prosthesis, average subsidence was 2.2 mm and significant subsidence occurred in 17.3%. Patient BMI was associated with subsidence. Revision surgery related to subsidence was infrequent (0.4%).

Irregular porous titanium enhances implant stability and bone ingrowth in an intra-articular ovine model.

Two commercially available porous coatings, Gription and Porocoat, were compared for the first time in a challenging intra-articular, weight-bearing, ovine model. Gription has evolved from Porocoat and has higher porosity, coefficient of friction, and microtextured topography, which are expected to enhance bone ingrowth. Cylindrical implants were press-fit into the weight-bearing regions of ovine femoral condyles and bone ingrowth and fixation strength evaluated 4, 8, and 16 weeks postoperatively. Biomechanical push-out tests were performed on lateral femoral condyles (LFCs) to evaluate the strength of the bone-implant interface. Bone ingrowth was assessed in medial femoral condyles (MFCs) as well as implants retrieved from LFCs following biomechanical testing using backscattered electron microscopy and histology. By 16 weeks, Gription-coated implants exhibited higher force (2455 ± 1362 vs. 1002 ± 1466 N; p = 0.046) and stress (12.60 ± 6.99 vs. 5.14 ± 7.53 MPa; p = 0.046) at failure, and trended towards higher stiffness (11,510 ± 7645 vs. 5010 ± 8374 N/mm; p = 0.061) and modulus of elasticity (591 ± 392 vs. 256 ± 431 MPa; p = 0.061). A strong, positive correlation was detected between bone ingrowth in LFC implants and failure force (r = 0.93, p < 10-13 ). By 16 weeks, bone ingrowth in Gription-coated implants in MFCs was 10.50 ± 6.31% compared to 5.88 ± 2.77% in Porocoat (p = 0.095). Observations of the bone-implant interface, made following push-out testing, showed more bony material consistently adhered to Gription compared to Porocoat at all three time points. Gription provided superior fixation strength and bone ingrowth by 16 weeks.

Outcomes of Bulk Fresh Osteochondral Allografts for Cartilage Restoration in the Knee.

BACKGROUND: Symptomatic osteochondral defects of the knee in young patients can cause substantial disability and predispose to osteoarthritis. Fresh osteochondral allografts (FOCAs) are a treatment option for such defects. With our institution having one of the longest-running FOCA programs, we investigated the long-term outcomes of bulk FOCA in the knee, focusing on graft survivorship, function, complications, and reoperation. METHODS: A total of 244 patients underwent bulk FOCA in the knee from 1972 to 2018, with a mean age of 37.8 years (range, 10 to 75 years) and a mean follow-up of 9.0 years (range, 1.0 to 29.8 years). Cartilage defects were very large and uncontained, such that they were not amenable to plug transplantation. Survivorship according to Kaplan-Meier analysis was the primary outcome, and failure was defined as conversion to total knee arthroplasty, repeat allograft, graft removal, knee arthrodesis, or amputation. Functional outcome was evaluated with use of the modified Hospital for Special Surgery (mHSS) score, and radiographic evidence of osteoarthritis was classified with use of the Kellgren-Lawrence grading scale. RESULTS: Graft survivorship was 86.6% at 5 years, 73.3% at 10 years, 58.1% at 15 years, 43.7% at 20 years, 31.9% at 25 years, and 22.6% at 30 years. The most common complications were pain (14.8%), malalignment (13.9%), and stiffness (5.8%). A total of 93 grafts (38.1%) failed at a mean of 11.0 years (range, 0.5 to 34.0 years). The mean mHSS score improved significantly, from 68.7 (range, 19 to 91) preoperatively to 80.3 (range, 52 to 100) at the time of the latest follow-up (p < 0.001). Preoperative mHSS score had a negative correlation with Kellgren-Lawrence grade at the time of the latest follow-up. Multivariate analysis revealed that graft location (i.e., medial-sided or multiple grafts) and increased age were significantly negatively associated with survival. Ten-year survival was >80% in patients below 50 years old, but <40% in patients >60 years old. CONCLUSIONS: Bulk FOCA provided promising long-term graft survival and functional improvement in patients <50 years old. It can delay or prevent the need for total knee arthroplasty in young patients. Older patients and patients with a medial-sided graft, or multiple grafts within the same knee, had a less favorable prognosis. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Return to Paralympic Rowing After Partial Joint Transplantation: A Case Report.

CASE: A 24-year-old competitive rower suffered a severe road injury to the medial aspect of his knee. He was referred to us for a partial joint transplantation consisting of a medial tibiofemoral fresh osteochondral allograft (FOCA), medial collateral ligament, meniscal allograft, and osteotomy. Two years after reconstruction, the patient won a bronze medal in the Summer Paralympics. At the 6-year follow-up, he demonstrates excellent clinical and radiographic outcomes and high satisfaction. CONCLUSION: For extensive knee injuries with large, complex defects, FOCA with concomitant meniscal allograft transplantation, ligamentous allograft, and osteotomy may be considered in high-demand athletes who wish to return to play.

Periacetabular Osteotomy and Femoral Head Allograft for Hip Dysplasia and Femoral Head Cyst: A Case Report.

CASE: A 34-year-old woman with developmental dysplasia of the hip (DDH) presented with chronic left hip pain related to a femoral head cyst. The patient strongly preferred a joint-preserving option. Periacetabular osteotomy (PAO) has shown reliable options for managing DDH, and femoral head fresh osteochondral allograft (FOCA) can be performed for cysts. We performed these procedures concomitantly for the first time. At 1-year follow-up, the patient had functional, pain-free motion and high satisfaction. CONCLUSION: PAO and femoral head FOCA can be performed concomitantly with a common, anterior hip approach. They are a viable, joint-preserving option for patients with DDH and osteochondral lesions.

Midterm Outcomes After Reconstruction of Superolateral Acetabular Defects Using Flying Buttress Porous Tantalum Augments During Revision Total Hip Arthroplasty.

BACKGROUND: Porous tantalum augments are versatile tools in reconstructing complex acetabular defects during revision total hip arthroplasty (THA). This study examines the clinical and radiographic outcomes of porous tantalum augments placed in the type I (flying buttress) configuration at two to 17-year follow-up in the largest cohort to-date in the literature. METHODS: We retrospectively analyzed 59 consecutive revision THAs involving the use of flying buttress augments between 2003 and 2018. The mean patient age and follow-up duration were 63.9 ± 11.6 years (range, 35-87) and 8 years (range, 2-17), respectively. The Oxford hip score was used to assess clinical outcome. The modified Moore classification was used to assess acetabular augment and shell osseointegration. Kaplan-Meier survival analysis with 95% confidence interval (CI) was used to assess implant survivorship. RESULTS: The mean Oxford hip score improved from 15.9 ± 6.2 preoperatively to 35.0 ± 6.5 at a mean follow-up of eight years (P < .0001). Radiographic assessment using the modified Moore classification demonstrated five signs of osseointegration in 49 hips (83.1%), four signs in six hips (10.2%), three signs in one hip (1.7%), and one sign in one hip (1.7%). Kaplan-Meier analysis demonstrated ten-year survivorship of 88.9% (95% CI 74.4-95.4) with all-cause revision as end point and 94.3% (95% CI 83.1-98.2) with revision for acetabular aseptic loosening as end point. CONCLUSION: Treatment of superolateral acetabular defects during revision THA using porous tantalum augments placed in the type I (flying buttress) configuration provides excellent implant survivorship and favorable clinical outcomes at mid-term follow-up. LEVEL OF EVIDENCE: Therapeutic Level IV.

Biomechanical optimization of the far cortical locking technique for early healing of distal femur fractures.

This finite element study optimized far cortical locking (FCL) technology for early callus formation in distal femur fracture fixation with a 9-hole plate using FCL screws proximal to, and standard locking screws distal to, the fracture. Analyses were done for 120 possible FCL screw configurations by varying FCL screw distribution and number. A hip joint force of 700 N (i.e. 100% x body weight) was used, which corresponds to a typical 140 N "toe-touch" foot-to-ground force (i.e. 20% x body weight) suggested to patients immediately after surgery. Increased FCL screw distribution (i.e. shorter plate working length) caused a decrease at the medial side and an increase at the lateral side of the axial interfragmentary motion (AIM), mildly affected shaft and condylar cortex Von Mises max stress (σMAX), increased plate σMAX, and decreased shaft FCL screw and condylar locking screw σMAX. Increased FCL screw number decreased AIM and σMAX on the shaft cortex, condylar cortex, plate, and FCL screws, but not condylar screws. The optimal FCL screw configuration had 3 FCL screws in plate holes #1, 5, and 6 (proximal to distal) for optimal AIM of 0.2 - 1 mm and reduce shear fracture motion, thereby encouraging early callus formation.

Does Trochanteric Osteotomy Length Affect the Amount of Proximal Trochanteric Migration During Revision Total Hip Arthroplasty?

BACKGROUND: Nonunion and proximal trochanteric migration is a known complication of trochanteric osteotomy. This study examines the effect of osteotomy length on proximal greater trochanter (GT) migration. METHODS: We analyzed 113 modified trochanteric slide osteotomies and 73 extended trochanteric osteotomies performed between 2008 and 2016. All osteotomies were fixed using cerclage wires and had minimum 6-month radiographic follow-up. Spearman correlations were used to assess association between osteotomy length and GT migration distance. Chi-squared test and logistic regression were used to assess association between patient and surgical factors and GT migration >1 cm. Receiver operating characteristic curves were constructed to determine the optimal cutoff osteotomy length for predicting GT migration >1cm. RESULTS: Mean osteotomy length was 6.1 cm (range 3-12) for modified trochanteric slide osteotomies and 14.8 cm (range 8-23) for extended trochanteric osteotomies. Osteotomy length was negatively correlated (r = -0.340, P < .001) with GT migration distance. Longer osteotomy length was protective against GT migration >1 cm (odds ratio 0.67, P = .002). Receiver operating characteristic curve analysis demonstrated an optimal cutoff osteotomy length of 9.8 cm for predicting GT migration >1 cm (sensitivity 0.971, specificity 0.461). Among osteotomies <10 cm, those fixed using at least one distal wire below the lesser trochanter and vastus ridge demonstrated less mean GT migration (3.86 vs 7.12 mm, P = .009) and higher mean union rate (68.8% vs 31.2%, P < .001). CONCLUSION: Osteotomies shorter than 10 cm are at higher risk of developing proximal GT migration >1 cm. A distal cerclage wire below the lesser trochanter and vastus ridge may help decrease the amount of GT migration. LEVEL OF EVIDENCE: Prognostic Level IV.

Long-Term Results of Treating Large Posttraumatic Tibial Plateau Lesions with Fresh Osteochondral Allograft Transplantation.

BACKGROUND: The use of fresh osteochondral allograft (FOCA) transplantation is a treatment option for large posttraumatic tibial osteochondral defects in young, high-demand patients. We aimed to assess the long-term outcomes of this procedure and factors impacting graft survivorship. METHODS: Evaluated were patients with a posttraumatic tibial plateau defect of >3 cm in diameter and >1 cm in depth who were treated with use of a FOCA, with or without a realignment osteotomy, before September 2007. The primary outcome was survivorship according to Kaplan-Meier analysis, with conversion to arthroplasty or another allograft procedure as the end point. The secondary outcome was the functional outcome of knees with a surviving FOCA, as assessed using the modified Hospital for Special Surgery (mHSS) scoring system. Multivariate Cox regression analysis of the role of potential variables was performed for both outcomes. RESULTS: Included were 113 patients (67 female) with a mean age at the time of the index surgery of 43 years (range, 24 to 72 years) and a mean follow-up of 13.8 years (range, 1.7 to 34 years). Forty-eight conversions to arthroplasty or another FOCA procedure had been performed at a mean of 11.6 years (range, 1.7 to 34 years) after the index surgery. The remaining 65 patients had a mean follow-up of 15.5 years (range, 4.3 to 31.7 years). The mean mHSS score among those with a surviving FOCA was 85.5 (range, 56 to 100) at the most recent follow-up, which was significantly higher than the preoperative value of 69 (range, 48 to 85) (p < 0.001). Graft survivorship was 90% at 5 years, 79% at 10 years, 64% at 15 years, and 47% at 20 years. Complications included infection (1.8%), nonunion (0.9%), and knee pain from hardware (8.8%). Multivariate analysis revealed that older age at the time of surgery, involvement of the medial plateau, and a higher number of previous surgeries were inversely associated with graft survivorship. Having a Workers' Compensation file was associated with less improvement in the mHSS score, and the score tended to decline over time for knees with a surviving FOCA. CONCLUSIONS: FOCA transplantation is a viable option for posttraumatic tibial osteochondral defects, with satisfactory survivorship and functional outcome. Although approximately half of the patients in our study demonstrated graft failure by 20 years, FOCA was an excellent option that delayed the need for arthroplasty. Older patients, those with medial defects, and those with multiple previous surgeries had a less favorable prognosis. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Patient and Caregiver Understanding of Prognosis After Hip Fracture.

BACKGROUND: Hip fracture (HF) is common and requires communication between patient, family, surgeons, and hospitalists. Patient and family understanding of the seriousness of HF is unclear. METHODS: We interviewed older patients (age > 65 years) hospitalized with HF at two Canadian academic hospitals, or their surrogate decision-makers (SDMs). We used qualitative methods to explore understanding of HF treatment options and prognosis. Participants estimated probability of mortality and living independently 30 days after surgery. Results were compared with estimates from the National Surgery Quality Improvement Program (NSQIP) surgical risk calculator. RESULTS: 9 patients and 3 SDMs were interviewed. Mean age of 12 patients was 82.5 years (75% female). Participants were uncertain about recovery timeline and degree of functional recovery, as well as content and duration of rehabilitation. Participants' mean estimated 30-day mortality of 6.7% did not differ significantly from estimated mortality predicted by NSQIP (7.5%; p = .88). Participants' mean estimated probability of living independently 30 days after surgery was 90.8% (range 65-100%). CONCLUSIONS: Older patients and SDMs lack understanding about prognosis and functional recovery even after providing informed consent for HF surgery. Clinical teams should improve communication of prognosis and recovery information to patients and surrogates.

Revision Total Knee Arthroplasty for the Management of Periprosthetic Fractures.

Periprosthetic fractures after total knee arthroplasty (TKA) can present reconstructive challenges. Not only is the procedure technically complex, but patients with these fractures may have multiple comorbidities, making them prone to postoperative complications. Early mobilization is particularly beneficial in patients with multiple comorbidities. Certain patient factors and fracture types may make revision TKA the ideal management option. Periprosthetic fractures around the knee implant occur most frequently in the distal femur, followed by the tibia and the patella. Risk factors typically are grouped into patient factors (eg, osteoporosis, obesity) and surgical factors (eg, anterior notching, implant malposition). Surgical options for periprosthetic fractures that involve the distal femur or proximal tibia include reconstruction of the bone stock with augments or metal cones or replacement with an endoprosthesis.

The Use of a Supra-Acetabular Antibiotic-Loaded Cement Shelf to Improve Hip Stability in First-Stage Infected Total Hip Arthroplasty.

BACKGROUND: Antibiotic-loaded cement spacers in first-stage revision total hip arthroplasty (THA) for managing infection are associated with high dislocation and fracture rates. The aim of this study was to report the use of an antibiotic-loaded cemented supra-acetabular roof augmentation to reinforce hip stability after cement spacer insertion for first-stage total hip revision in the treatment of infected THA. METHODS: We retrospectively reviewed a consecutive series of 50 THAs involving 47 patients with an infected hip requiring staged revisions of THA. We documented dislocation, reinfection, and time for revision and outcome. RESULTS: There were no cases of hip dislocation, cement fractures, or any other technical complications associated with the use of the roof augmentation lip. Thirteen cases (26%) had a cemented spacer for longer than 120 days. Seven (14%) cases had recurrent infection after staged revision THA. CONCLUSION: The antibiotic-loaded cemented supra-acetabular roof augment improved femoral head spacer coverage for patients requiring a staged revision THA for infection.

Biomechanical comparison of the human cadaveric pelvis with a fourth generation composite model.

The use of cadavers for orthopaedic biomechanics research is well established, but presents difficulties to researchers in terms of cost, biosafety, availability, and ease of use. High fidelity composite models of human bone have been developed for use in biomechanical studies. While several studies have utilized composite models of the human pelvis for testing orthopaedic reconstruction techniques, few biomechanical comparisons of the properties of cadaveric and composite pelves exist. The aim of this study was to compare the mechanical properties of cadaveric pelves to those of the 4th generation composite model. An Instron ElectroPuls E10000 mechanical testing machine was used to load specimens with orientation, boundary conditions and degrees of freedom that approximated those occurring during the single legged phase of walking, including hip abductor force. Each specimen was instrumented with strain gauge rosettes. Overall specimen stiffness and principal strains were calculated from the test data. Composite specimens showed significantly higher overall stiffness and slightly less overall variability between specimens (composite K=1448±54N/m, cadaver K=832±62N/m; p<0.0001). Strains measured at specific sites in the composite models and cadavers were similar (but did differ) only when the applied load was scaled to overall construct stiffness. This finding regarding strain distribution and the difference in overall stiffness must be accounted for when using these composite models for biomechanics research. Altering the cortical wall thickness or tuning the elastic moduli of the composite material may improve future generations of the composite model.

Closed suction drainage has no benefits in revision total hip arthroplasty: a randomized controlled trial.

PURPOSE: Several studies have failed to show significant benefits of closed suction drainage (CSD) in routine primary total hip arthroplasty (THA). However, blood loss, haematoma formation and wound complications are generally much greater in revision THA as compared to primary THA. The purpose of this study was to determine if CSD is beneficial for revision THA patients. METHODS: We conducted a prospective, randomized, controlled trial at our institution between July 2013 and July 2014. Eighty-eight patients undergoing revision THA were enrolled and randomly assigned to receive a CSD (n = 44) or to not receive a CSD (n = 44). All first-stage revision surgeries for infection were excluded. Primary outcomes were haemoglobin loss and number of patients transfused. Secondary outcomes included functional outcome evaluated with Harris hip score (HHS), pain evaluated with visual analogue scale (VAS), and length of hospital stay. RESULTS: There were significantly more patients in the CSD group that required blood transfusions (20/44 as compared to 11/44, p = 0.04). Patients in the no CSD group were discharged earlier than patients in the CSD group (4.3 days as compared to 5.4 days, p = 0.002). No statistical significant difference was found in the HHS or pain VAS between the groups. CONCLUSIONS: This study did not demonstrate any benefit with the use of CSD for revision THA with regard to wound related complications, infection or early functional outcome. Post-operative blood loss, transfusion rate, and length of hospital stay may be higher with CSD.

The results of two-stage revision TKA using Ceftazidime-Vancomycin-impregnated cement articulating spacers in Tsukayama Type II periprosthetic joint infections.

PURPOSE: This study examined the success and factors associated with failure, of using cement spacers impregnated with high-dose Ceftazidime and Vancomycin when performing two-stage revision for infected total knee arthroplasty (TKA). METHODS: A retrospective analysis was performed using a prospectively collected database of 82 patients (median age 68 years, range 39-87) with a confirmed deep TKA infection treated with a two-stage revision. All cement spacers were impregnated with high-dose Ceftazidime and Vancomycin. The rate of success was recorded-an association between failure of treatment, and patient factors, previous surgical treatment, and microbial characteristics was sought. RESULTS: The mean time to infection from index arthroplasty was 45 months (range 3-240). The initial two-stage revision was successful in 70/82 patients (85.4 %), who remained free of infection at average follow-up of 36.2 months (range 24-85). A second two-stage revision for infection was required in 12/82 patients (14.6 %), which was successful in 4/12 (33 %). A third two-stage revision was performed in three patients, all of whom had a polymicrobial infection of which only one patient had successful eradication of infection. Recurrent infection was correlated with irrigation and debridement with implant retention prior to initial two-stage revision (p < 0.01), polymicrobial infections (p = 0.035), and infections presenting <6 months after index surgery (p = 0.031). No correlation was seen with age, BMI, type of organism, diabetes mellitus, or Charlson Comorbidity Index. CONCLUSION: The findings of this study suggest that the combination of Ceftazidime and Vancomycin in cement spacers is as efficacious as other published single or combined antibiotic mixtures, which is clinically relevant to clinicians treating this difficult problem in the setting of patients with compromised renal function.

The focally constrained liner is a reasonable option for revision of unstable total hip arthroplasty.

PURPOSE: Revision surgery for a patient with previous recurrent dislocations or abductor muscle dysfunction has been considered to be a complication-prone procedure regardless of the type of constrained implant used. We investigated the survivorship of a focally constrained acetabular liner used for revision total hip arthroplasty in patients with abductor insufficiency or previous recurrent dislocations. METHODS: We retrospectively reviewed 98 patients in whom a focally constrained acetabular liner was used to treat abductor insufficiency or previous recurrent dislocations. The mean age was 69.4 years (37-92) and 64 of these were females. Previously, the patients had undergone a mean of two (1-5) revisions. The mean follow-up was 38 (12-66) months. Kaplan-Meier survival curves were calculated and Log-rank test was used to test the difference in survivorship between patients with abductor insufficiency and previous dislocations. RESULTS: Sixteen patients needed a further re-revision for any cause. Thus, the revision-free survivorship was 84.3 % at five years. Five patients suffered a dislocation with a mean of five months post-operatively and were managed with repeat revision. Five patients failed at the implant-host bone interface. Three of these failures occurred after cementing the constrained liner into a pre-existing shell. CONCLUSIONS: The focally constrained liner provided a reasonable option for revision total hip arthroplasty in patients with hip instability. Failures were observed in patients with acetabular osteolysis but seemingly well-fixed component and unrecognized impingement.

Arthroplasty for unstable pertrochanteric hip fractures may offer a lower re-operation rate as compared to cephalomedullary nailing.

PURPOSE: Cephalomedullary (CM) nailing is widely used for the treatment of pertrochanteric hip fractures. Fixation failures with CM nailing tend to occur in unstable fracture patterns often necessitating revision surgery. The purpose of this study was to compare the complications and clinical outcomes of primary arthroplasty to CM nailing for the treatment of unstable pertrochanteric hip fractures. METHODS: We conducted an age-, sex-, and fracture type-matched case-controlled study and identified 29 patients who underwent hip arthroplasty for an unstable pertrochanteric fracture (AO/OTA classification type 31A2.2/3 and 31.A3) at our institution. Their outcome was compared to a matched control group of 29 patients treated with a CM nail. RESULTS: There was one major complication in the arthroplasty group (3.4 %), whereas there were six major complications in the nailing group (20.7 %) (P = 0.04). We found no significant difference between the groups with regards to blood loss, operative time, hospitalization time and the number of patients discharged to rehabilitation. Clinical outcome measured with Oxford hip score and SF-12 at the time of final follow-up was not significantly different between the groups. CONCLUSIONS: Arthroplasty is a viable option for treatment of unstable pertrochanteric fractures in an elderly population. Arthroplasty may offer a lower re-operation rate in the treatment of unstable pertrochanteric hip fractures as compared to CM nailing.

Arthroplasty for Pertrochanteric Hip Fractures.

The mainstay of treatment of pertrochanteric fractures is internal fixation using a sliding hip screw or a cephalomedullary device. However, in patients with ipsilateral hip osteoarthritis or avascular necrosis of the femoral head, or inflammatory arthritis, arthroplasty should be considered as the primary treatment modality to reduce the likelihood of a secondary procedure. Unstable fracture patterns with concomitant poor bone quality represent a challenge for internal fixation, with high rates of lag screw cut-out and hardware failure. Prosthetic replacement for unstable pertrochanteric fractures has therefore been considered as an alternative primary treatment option. Further prospective randomized trials are required.

Complications following conversion of a hip hemiarthroplasty to a total hip arthroplasty.

PURPOSE: Conversion of hip hemiarthroplasty to total hip arthroplasty (CTHA) is a complication-prone procedure with high dislocation rates and early component loosening. The purpose of this study was to evaluate the complications of CTHA performed using contemporary implants. METHODS: Forty-six patients who had CTHA were retrospectively matched to a control group of 46 patients who had a first-time THA revision. The mean follow-up was 47 (range 6-149) and 23 (range 6-139) months for CTHA and control groups, respectively. Radiographs taken at the last follow-up visit were evaluated for signs of loosening or other modes of failure. Clinical outcome was evaluated with the Harris Hip Score (HHS). RESULTS: Complications occurred in five patients (10.9 %) in the CTHA group, and all required repeat revision. Two patients (4.3 %) were revised due to recurrent dislocation. The other re-revisions were done for acetabular or femoral component loosening and deep infection. In the control group, complications occurred in six patients (13.0 %), and three (6.5 %) were revised with a constrained liner due to recurrent dislocations. CONCLUSIONS: Dislocation rates and re-revision for CTHA were not significantly different than those of first-time THA revision when using contemporary revision implants.

Periprosthetic supracondylar femoral fractures following knee arthroplasty: a biomechanical comparison of four methods of fixation.

PURPOSE: The aim of this study was to determine the biomechanical properties of four fixation options for periprosthetic supracondylar femoral fractures. METHODS: Fourth-generation composite femurs were implanted with a posterior-stabilizing femoral component of total knee arthroplasty. All femurs were osteotomized to produce a AO/OTA 33-A3 fracture pattern and four different constructs were tested: (1) non-locking plate; (2) polyaxial locking plate; (3) intramedullary fibular strut allograft with polyaxial locking plate; (4) retrograde intramedullary nail. The composite femurs underwent non-destructive tests to determine construct stiffness in axial and torsional cyclic loading. The final testing consisted of quasi-static axial loading until failure. RESULTS: Under cyclic torsional loading, the retrograde intramedullary nail was less stiff than non-locking plate, polyaxial locking plate and intramedullary fibular strut allograft with polyaxial locking plate (p = 0.046). No differences were detected in cyclic axial loading between the different constructs. During quasi-static axial loading to failure, the intramedullary nail achieved the highest axial stiffness while the non-locking plate showed the lowest (p = 0.036). CONCLUSIONS: The intramedullary fibular strut allograft with polyaxial locking plate did not prove to be significantly better to the polyaxial locking plate only in a periprosthetic distal femur fracture model.