Ipsilateral above-knee amputation in patient with recurrent dislocation after total hip arthroplasty: A case report.

Amputation secondary to vascular complications of recurrent dislocations after total hip arthroplasty (THA) is an extremely rare. We describe an unusual case of above-knee amputation resulting from vascular complications after recurrent dislocations of a THA. A 63-year-old male patient with walking pain and limp has a history of acetabular fracture and central dislocation of the femoral head. He was diagnosed as post-traumatic arthritis and subluxation of the femoral head and suffered from four similar dislocations in 210 days after the THA. The patient received conservative treatment after every hip dislocation. However, four months after the fourth reduction, the emergent femoral artery and popliteal artery exploration and catheter thrombectomy were performed at another hospital. An ipsilateral above-knee amputation was done after sepsis and failure of the revascularization procedure. Clinicians should be cognizant that above-knee amputation resulting from vascular complications after recurrent dislocations of a THA may occur. The lack of adherence to critical treatment may have led to the severe outcome of amputation. In conclusion, patient education and compliance are essential for both the treatment of hip dislocations and arterial occlusion. More active and effective measures should be used to prevent such catastrophic events.

Three-dimensional femur morphology analysis for the optimal location of subtrochanteric osteotomy with an implanted Wagner cone stem in total hip arthroplasty for Crowe type IV developmental dysplasia of the hip.

BACKGROUND: This study aimed to accurately evaluate the matching of proximal and distal femoral segments and fitting of the femur-femoral stem in patients with Crowe type IV developmental dysplasia of the hip (DDH) who have undergone subtrochanteric osteotomy at different locations with an implanted Wagner cone stem to improve the rate of the bone union at the osteotomy site. METHODS: Three-dimensional femur morphology of 40 patients with Crowe type IV DDH was evaluated at each cross-section to determine the femoral cortical bone area. This study focused on five osteotomy lengths (2.5, 3, 3.5, 4, and 4.5 cm). The overlapped area between the proximal and distal cortical bone segments was defined as the contact area (S, mm2), and the contact area to distal cortical bone area ratio was defined as the coincidence rate (R). Three indicators were used to evaluate the matching and fitting of the osteotomy sites with the implanted Wagner cone stems: (1) higher S and R between the proximal and distal segments; (2) the effective fixation length of the femoral stem at the distal segments being at least 1.5 cm; and (3) osteotomy did not involve the isthmus. RESULTS: In all groups, S significantly decreased in the two proximal levels above the 0.5 cm level below the lesser trochanter (LT) compared with those below this level. In comparison, at osteotomy lengths from 2.5 to 4 cm, R significantly decreased in the three proximal levels. The optimal osteotomy levels ranged from 1.5 and 2.5 cm below the LT for an appropriately sized stem. CONCLUSIONS: Subtrochanteric osteotomy at the optimal level not only ensures fitting of the femur-femoral stem but also meets the requirements of a higher S and R to ensure adequate reduction and stabilization at the osteotomy site, which may contribute to the bone union. Although the optimal osteotomy level varies with the size of the femoral stem and the length of the subtrochanteric osteotomy, the optimal osteotomy levels for an appropriately sized Wagner cone femoral stem implantation range from 1.5 to 2.5 cm below the LT.

Effect of open-wedge high tibial osteotomy and lateral patellofemoral retinacular release on patellar position: an X-ray imaging-based comparative study.

Background: Open-wedge high tibial osteotomy (OWHTO) may cause adverse changes in the mechanical environment of the patellofemoral joint. For patients with lateral patellar compression syndrome or patellofemoral arthritis, intraoperative management is still challenging. The effect of lateral retinacular release (LRR) on patellofemoral joint mechanics after OWHTO remains unclear. Our study aimed to evaluate the effect of OWHTO and LRR on the patellar position based on lateral and axial radiographs of the knee joint. Methods: The study comprised 101 knees (OWHTO group) undergoing OWHTO alone and 30 knees (LRR group) undergoing OWHTO and concomitant LRR. The following radiological parameters were statistically analyzed preoperatively and postoperatively: femoral tibial angle (FTA), medial proximal tibial angle (MPTA), weight-bearing line percentage (WBLP), Caton-Deschamps index (CDI), Insall-Salvati index (ISI), lateral patellar tilt angle (LPTA), and lateral patellar shift (LPS). The follow-up duration ranged from 6 to 38 months, with a mean of 13.51±6.84 months in the OWHTO group and 12.47±7.81 months in the LRR group. The Kellgren-Lawrence (KL) grading system was used to evaluate changes in patellofemoral osteoarthritis (OA). Results: Regarding the patellar height, preliminary analysis demonstrated a statistically significant decrease in the CDI and ISI in both groups (P<0.05). However, there was no significant difference in changes in CDI or ISI between the groups (P>0.05). In the OWHTO group, although there was a significant increase in the LPTA (P=0.033), the postoperative decrease in the LPS was not significant (P=0.981). In the LRR group, both the LPTA and LPS significantly decreased postoperatively (P=0.000). The mean changes in LPS were 0.03 mm in the OWHTO group and 1.44 mm in the LRR group, indicating a significant change in LPS (P=0.000). However, there was no significant difference in changes in LPTA between the groups, which was contrary to our expectations. Imaging showed no change in patellofemoral OA in the LRR group and progressive changes (from KL grade I to II) in patellofemoral OA in 2 (1.98%) patients in the OWHTO group. Conclusions: OWHTO can cause a significant decrease in patellar height and an increase in lateral tilt. LRR can significantly improve the lateral tilt and shift of the patella. The concomitant arthroscopic LRR should be considered for the treatment of patients with lateral patellar compression syndrome or patellofemoral arthritis.

[Propensity score-matched study of uni-condylar arthroplasty in elderly patients with knee osteoarthritis].

OBJECTIVE: To investigate the clinical efficacy of unicompartmental knee arthroplasty (UKA) in the treatment of knee osteoarthritis in patients over 75 years old. METHODS: The clinical efficacy of primary fixed platform UKA in patients with osteoarthritis, was retrospectively analyzed from October 2014 to November 2020. Age, body mass index (BMI), range of motion (ROM), preoperative joint function score, the quality of life score and other preoperative indicators were measured by propensity score matching (PSM). The patients were divided into elderly group (≥75 years old) and control group (<75 years old). Oxford knee score(OKS), Western Ontario McMaster Universities osteoarthritis index(WOMAC), Short Form-12 including physical component summary (PCS), mental component summary(MCS), minimal clinically important difference(MCID ) and clinical complications were evaluated preoperatively and postoperatively. RESULTS: A total of 514 patients were analyzed, 428 patients fulfilled the inclusion criteria. A propensity-score matching study was conducted to eliminate confounding factors. After 1∶2 propensity match, there were 84 patients in elderly group (≥75 years), age ranged from 75 to 88 years old, with an average of (78.79±3.08) years old, and 168 patients in control group (<75 years), age ranged from 47 to 74 years old, with an average of (64.10±5.96)years old. The follow-up duration of two groups ranged from 12 to 84 months with an average of (29.35±16.52) months in elderly group, and 12 to 85 months with an average of (31.83±17.34) months in control group. There was only significant difference in age between the elderly and control groups preoperatively (P<0.01). Postoperatively, the elderly group showed significantly higher WOMAC (P<0.01) and lower SF-12 PCS scores (P<0.01) as compared to the control group. There was no significant difference between the elderly group and the control group in knee range of motion, OKS and the proportion of each scoring system reaching the minimum clinical difference value (P>0.05). In the aspect of preperative complications, the elderly group exhibited more surgical site complications and postoperative delirium compared to control group(P<0.05). The differences in other indicators including deep vein thrombosis, acute urinary retention, cardiovascular events, cerebrovascular events and radiolucent lines around prothesis were not statistically significant(P>0.05). CONCLUSION: UKA in the treatment of elderly patients over 75 years old with knee osteoarthritis was safe and feasible, and could obtain satisfactory short-term efficacy.

[Effect of open wedge tibial high osteotomy on patella position and joint function].

OBJECTIVE: To investigate the effect of open wedge tibial high osteotomy on patella position, anterior knee pain and joint function. METHODS: From June 2016 to June 2021, 109 patients (111 knees) with medial knee osteoarthropathy treated by open wedge tibial high osteotomy were included according to the inclusion and exclusion criteria, including 41 males and 68 females;the age ranged from 38 to 78 years old with an average of(57.98±7.07) years;the course of disease ranged from 1 to 36 months with an average of (8.58±6.91) months. The femoral tibial angle(FTA), medial proximal tibial angle(MPTA), weight bearing line(WBL) percentage, Caton Deschamps index (CD index), lateral patella tilt angle (LPTA) and lateral patella shift (LPS) were observed and compared before and after operation. Lysholm score was used to evaluate the knee function, visual analogue scale(VAS) was used to evaluate the degree of anterior knee pain, and Kellgren Lawrence(K-L) grading system was used to evaluate the progress of patellofemoral osteoarthritis. RESULTS: All patients were followed up for 6 to 38 months with an average of (12.41±2.40) months. The preoperative FTA, MPTA, WBL percentage, CD index, and LPTA were significantly different from those at the last follow-up(P<0.05). There was no significant difference between before and after LPS operation(P=0.78). Lysholm score increased from (58.79±7.90) scores to (76.05±7.36) scores (P<0.05). The VAS of anterior knee pain decreased from (3.28±1.95) scores to(1.07±1.75) scores(P<0.05). Knee patellofemoral osteoarthritis showed progressive changes, but there was no significant difference in K-L grading before and after operation (P>0.05). CONCLUSION: After open wedge tibial high osteotomy, the position of patella is lowered and the patella is tilted outward, but the knee function and anterior knee pain are significantly improved. Adverse changes in patella position caused by open wedge tibial high osteotomy may not affect clinical outcomes.

Effect of platelet-rich plasma scaffolding combined with osteochondral autograft transfer for full-thickness articular cartilage defects of the femoral condyle.

We aimed to investigate the local application methods of platelet-rich plasma (PRP) and the effect and safety of PRP scaffolding combined with osteochondral autograft transfer (OAT) in the treatment of full-thickness articular cartilage defects of the femoral condyle. Patients with cartilage defects of the femoral condyle were treated with OAT combined with PRP scaffolding between July 2017 and December 2020. Preoperative magnetic resonance imaging (MRI) and computed tomography were utilized to assess the size, location, and severity of the osteochondral defects. X-ray and MRI images of the knee were obtained at the final follow-up to assess the osseointegration and integrity of the implanted articular cartilage. Osteoarthritic changes in the knee joint were evaluated using the Kellgren-Lawrence grading system. Clinical status was assessed using the visual analog scale (VAS), International Knee Documentation Committee (IKDC), and Lysholm scores before the treatment and at the final follow-up. Complications and patient satisfaction were recorded to assess the safety of this combination therapy. Twenty-one patients were recruited, with a mean follow-up duration of 18.23 ± 6.84 months. The mean lesion size was 2.3 ± 0.59 cm2. The mean platelet concentration in PRP at baseline was 6.27 ± 0.63 times greater than that in the peripheral blood. The VAS, IKDC, and Lysholm scores had improved significantly at the final follow-up (P< 0.001). No serious complications such as joint infection, deep venous thrombosis, or hematoma were observed. Eighteen patients (85.72%) were satisfied with their knee function and quality of life at the final follow-up. Three patients (14.28%) complained of mild anterior knee pain, which was relieved by oral administration of nonsteroidal anti-inflammatory drugs. MRI examinations of all patients showed bony consolidation and the defect surface was covered with cartilage-like tissue. X-ray evaluations indicated that osteoarthritis in two knees (9.5%) had progressed from grade 1 to grade 2 at the final follow-up. The preliminary results showed that OAT combined with PRP may be a safe and effective technique for the treatment of full-thickness articular cartilage defects in the knee.

Mid-Term Outcomes of Cemented Stem and Subtrochanteric Shortening Derotational Osteotomy in Total Hip Arthroplasty for Crowe IV Developmental Dysplasia.

OBJECTIVE: Performing subtrochanteric osteotomy with cemented components in patients with Crowe IV developmental dysplasia of the hip (DDH) is technically challenging and not widely reported. This study aimed to evaluate the mid-term outcomes of cemented stem total hip arthroplasty (THA) with subtrochanteric femoral shortening and transverse derotational osteotomy in patients with Crowe IV DDH. METHODS: Data collected from patients with Crowe IV DDH who underwent cemented stem THA with subtrochanteric femoral shortening and transverse derotational osteotomy between 2010 and 2018 were retrospectively evaluated. The cemented Lubinus SP II femoral component and the cementless CombiCup acetabular component were used together in all cases. These data, including Harris hip scores, limb length discrepancy (LLD), severity of limp, Trendelenburg test, bone union, length of the resected femur, limb lengthening, level of the osteotomy site, and length bridging the osteotomy site, as well as complications, were analyzed. A paired Student t-test was used to analyze continuous variables, categorical data were compared using Fisher's exact probability test, and correlation analysis was performed using Spearman's rank correlation coefficient. RESULTS: Among 14 included patients (10 females and four males), the mean age was 60.4 years (range, 47-73). The mean follow-up period was 49.1 months, and no patient was lost to follow-up. The mean Harris hip score improved from 40.7 to 87.7. The mean LLD decreased from 52 to 12.7 mm. The mean length of the excised femoral segment was 38.4 mm, and the mean length of limb lengthening was 27.1 mm. The mean distance between the osteotomy site and the lesser trochanter was 21.1 mm after surgery. The mean length of the femoral stem bridging the osteotomy site was 97.6 mm. Finally, the mean osteotomy union time was 10.6 months. No statistically significant correlation was found between the osteotomy union time and these factors. No neurological deficits were noted. Delayed union was observed in one patient, and postoperative dislocation was observed in two patients. Cement leakage into the osteotomy gap was observed in one patient, however, no revisions were required, and no signs of loosening or migration were observed. CONCLUSIONS: Cemented stem THA combined with subtrochanteric femoral shortening and transverse derotational osteotomy is safe and effective in treating patients with Crowe IV DDH. Rather than leading to nonunion, cement leakage may negatively affect bone healing.

The impact of novel anchored barbed suture for capsular closure on hospital length of stay after total knee arthroplasty: a retrospective cohort study.

OBJECTIVE: The aim was to evaluate whether using novel anchored barded suture for capsular closure can further shorten the length of stay following primary total knee arthroplasty (TKA) within existed enhanced recovery after surgery (ERAS) protocol in osteoarthritis patients. METHODS: A retrospective cohort study was conducted among osteoarthritis patients aged 18 to 80 years without major comorbidities who underwent primary unilateral TKA between January 2018 and December 2019 was conducted. The capsular closure techniques, interventions for ERAS, operation time and length of stay were collected via hospital electronic information system. Propensity-score matching was used to compensate for the difference in interventions for ERAS and patient characteristics. Subgroup comparison of patients treated under normal ERAS protocol was performed. RESULTS: Included were 315 patients with capsular closure by barded suture and 397 patients with interrupted capsular closure by traditional suture. Patients' characteristics and interventions for ERAS were balanced after propensity-score matching. The average postoperative length of stay in barded suture group was shorter than the compared group (2.10 ± 0.57 vs. 2.33 ± 0.80 days, p = 0.004), and with a significantly higher proportion of patients discharging within 2 days post procedure (88.0% vs. 70.7%, p < 0.001). The operation time for patients with barded suture closure was shorter compared to interrupted closure technique (100.90 ± 16.59 vs. 105.52 ± 18.47 min, p = 0.004). Subgroup analysis of patients treated under different levels ERAS protocol showed comparable results. CONCLUSION: The use of barded suture for capsular closure was associated with shorter length of stay after TKA compared to traditional suture, suggesting that barded suturing technique could be one effective intervention for ERAS.

Pseudotumor and delayed recurrent dislocation after total hip arthroplasty with a modular femoral neck: A case report.

RATIONALE: Pseudotumor formation after hip arthroplasty is a rare complication that can occur not only at the head-neck junction but also at the modular neck-stem junction. Dislocation is a challenging and common complication of primary and revision total hip arthroplasty compared with other complications. Similarly, the association between pseudotumors and delayed recurrent dislocation remains unclear. PATIENT CONCERNS: We report the case of a 73-year-old woman with pseudotumor formation after total hip arthroplasty combined with a modular femoral neck. A delayed recurrent dislocation occurred in this case. Approximately 4weeks after the first revision surgery, redislocation occurred. DIAGNOSIS: The patient was eventually diagnosed with delayed recurrent artificial hip dislocation combined with a periprosthetic pseudotumor of the right hip. INTERVENTIONS: During the first revision surgery, a thickened, indurated cyst measuring 8×3×8cm with a red-brown wall containing brown fluid was completely excised. A cemented stem, combined with a BIOLOX Forte ceramic head, was implanted. Approximately 4weeks after surgery, redislocation occurred, and we cemented an elevated rim liner on the acetabular component with a metal head. OUTCOMES: At the last follow-up, 49 months after revision surgery, the patient was asymptomatic with a Harris hip score of 90. The patient had a satisfactory prognosis after treatment. LESSONS: The application of the modular-neck stem should be cautiously performed, particularly for modular prostheses containing different alloys. Pseudotumors and insufficient soft-tissue tension both contribute to hip instability, which may eventually lead to delayed repeated dislocation. In addition, femoral offset must be considered. Cement-liner technology may be used for aging patients who are less active. This case report, focusing on pseudotumors and delayed recurrent dislocations, aimed to identify factors that may support this diagnosis, which is easy to miss. Consequently, it can provide further details on the treatment process and alert orthopedic surgeons to this infrequent but important cause of delayed recurrent dislocation.

Intra-articular injections of platelet-rich plasma vs. hyaluronic acid in patients with knee osteoarthritis: Preliminary follow-up results at 6-months.

The aim of the present study was to compare the clinical and economic benefits of intra-articular injections of platelet-rich plasma (PRP) and hyaluronic acid (HA) in Chinese patients with knee osteoarthritis (OA). A total of 86 patients (42 treated with PRP and 44 with HA) were treated with three weekly intra-articular injections. The inclusion criteria included patients between 18 and 75 years of age, with chronic knee pain or swelling lasting >3 months and X-ray findings of degenerative joint alterations according to the Kellgren-Lawrence score grade I-III. Clinical examinations were performed before treatment, at 1- and 6-month post-injection intervals. International Knee Documentation Committee subjective, Western Ontario and McMaster Universities and visual analogue scale scores were determined at each examination. Adverse reactions, average cost, treatment time and patient satisfaction were also recorded. Compared with patients injected with HA, PRP was found to be associated with increased and more severe post-injection pain and swelling, where the duration of adverse reactions was greater in the PRP group (P=0.02). During the follow-up evaluations, both groups showed statistically significant improvements in all clinical scores from pre-injection to 1- and 6-month assessments (P<0.05). However, no significant inter-group (PRP vs. HA) differences were observed in the clinical scores between the two follow-up time points. There were also no significant differences in clinical score between the groups with regards to the Kellgren-Lawrence grade I, II or III. The average cost of PRP injections was 22.8X that of HA administration and the average treatment time was 5X that of HA, but there was no significant difference in patient satisfaction. These preliminary results indicate that although PRP injections can significantly improve clinical outcome in patients with knee OA, PRP is not any more effective compared with HA. Furthermore, PRP injections are associated with higher costs and treatment times. Therefore, additional clinical studies are required before PRP injections can be considered as a first-line treatment option for knee OA.

A comprehensive program for enhanced management of femoral neck fractures including an enhanced recovery after surgery program: A retrospective study.

ABSTRACT: To retrospectively analyze the functional outcomes and complications in patients who underwent hip arthroplasty with enhanced recovery after surgery (ERAS) program for femoral neck fractures.Between June 2015 and May 2019, 1138 patients with femoral neck fractures were treated in our department. According to the Garden classification system, 467 cases were type III and 671 cases were type IV with an average age of 74.9 ±â€Š8.8 years (range, 59-96 years). All patients underwent hip arthroplasty with ERAS. The clinical outcomes of these patients were retrospectively analyzed at the final follow-up using the Harris hip score (HHS).The median follow-up was 21.2 months (range, 6-36 months). The mean time to surgery and the length of hospitalization after surgery were 2.4 and 2.2 days, respectively. Eight hundred and fifty-two patients (74.9%) were operated within 48 hours from admission, 1052 cases (92.4%) were discharged within 48 hours after surgery. Twelve patients (1.05%) were readmitted for prosthetic dislocation. None of the patients suffered from infection, periprosthetic fractures, and/or prosthetic loosening. The HHS at the final follow-up was 92.7 ±â€Š7.6, with an excellent or good rate of 90.2%.Patient-oriented ERAS optimizes the interventional measures during the perioperative period for geriatric patients with femoral neck fractures and can improve their short-term clinical outcomes without increased readmission rates.

Gene Expression Profiling of the Sciatic Nerve in Streptozotocin-Induced Diabetic Rats with Peripheral Neuropathy.

AIMS: To investigate the candidate biomarkers and molecular mechanisms involved in the early phase of experimental diabetic peripheral neuropathy (DPN). METHODS: Diabetes in Sprague-Dawley rats was induced with streptozotocin (STZ) treatment, followed with neurological tests and histological examinations to assess the neuropathic symptoms of DPN. Microarray was performed on the sciatic nerve tissues from control rats and DPN rats at then6th week after diabetes induction, and differentially expressed genes (DEGs) between them were identified and applied for further bioinformatic analyses. RESULTS: Experimental DPN rats were successfully constructed, presenting significantly decreased withdrawal threshold and motor nerve conduction velocity, and typical histological changes in the sciatic nerve. 597 DEGs (186 up- and 411 downregulated) were identified in DPN rats. DEGs from the 3 most highly connected clusters in the protein-protein interaction network were enriched for biological processes or pathways such as "cell division," "cell cycle," "protein phosphorylation," "chemokine signaling pathway," "neuropeptide signaling pathway," "response to drug," "cellular response to insulin stimulus," "PPAR signaling pathway," and "glycerophospholipid metabolism." Thirteen genes were identified as the hub DEGs in the PPI network. Eleven transcriptional factors (TFs) targeting 9 of the 13 hub DEGs were predicted. CONCLUSIONS: The present study identified a pool of candidate biomarkers such as Cdk1, C3, Mapk12, Agt, Adipoq, Cxcl2, and Mmp9 and molecular mechanisms which may be involved in the early phase of experimental DPN. The findings provide clues for exploring new strategies for the early diagnosis and treatment of DPN.

Arthroscopic all-inside repair with suture hook for horizontal tear of the lateral meniscus at the popliteal hiatus region: a preliminary report.

BACKGROUND: Arthroscopic surgery procedures vary depending on the types of meniscus tear, including meniscectomy and meniscus repair. Among the several types of meniscus tear, the horizontal tear of the lateral meniscus at the popliteal hiatus region is a common injury, and its surgical treatment is still inconsistent. METHODS: Between January 2018 and October 2018, 20 patients who underwent all-inside repair with suture hook for the horizontal tear of the lateral meniscus at the popliteal hiatus region were recruited. Any operative complication was recorded, and postoperative MRI scans were conducted at the 6 months. The clinical results were graded based on the scale of the Lysholm knee score preoperatively and at follow-up. RESULTS: No operative complications were recorded. Postoperative MRIs at the 6 months showed that there was no re-tear for all patients, though signal intensity remained high in T2-weighted MRI in the lateral meniscus for nine cases. The average preoperative Lysholm knee score was 58.6 ± 10.1, which increased significantly to 89.3 ± 7.8 (t = - 11.01, p = 0.001) at the last follow-up. Recurrence or aggravation of symptoms was not noted at the final follow-up. CONCLUSION: All-inside repair with suture hook may be a good option for the horizontal tear of the lateral meniscus at the popliteal hiatus region which preserves the meniscus; avoids iatrogenic injury on the adjacent popliteal tendon, common peroneal nerve, and inferior lateral geniculate artery.

[Fixed-bearing unicompartmental knee arthroplasty for medial compartmental knee osteoarthritis].

OBJECTIVE: To evaluate short-term clinical results of fixed-bearing unicompartmental knee arthroplasty (UKA) for patients with medial compartmental knee osteoarthritis. METHODS: From January 2015 to December 2017, 62 patients with medial compartmental knee osteoarthritis were treated by fixed-bearing UKA. Among them, including 19 males and 43 females, aged from 47 to 83 years old with an average of (65.3±8.2) years old. The courses of disease ranged from 5 to 72 months with an average of(19.4±14.3) months. Postoperative complications were observed, VAS score was used to observe degree of pain relief, Hospital for Special Surgery(HSS) score was used to evaluate clinical effects. RESULTS: All patients were followed up from 4 to 40 months with an average of(19.9 ±10.2) months. The incision healed well without blood transfusion, hospital stays ranged from 2 to 10 days with an average of (3.5±1.6) days. No deep infection, dislocation, loosing or per prosthetic fracture occurred after operation, while 1 patient suffered from posterior tibial vein thrombosis. HSS score improved from 69.9±7.2 before operation to 90.1±7.4 at final following-up, and 51 patients obtained excellent results, 9 patients good and 2 moderate. VAS score decreased from 3.8±0.9 before operation to 1.1±0.9 at final following-up. CONCLUSIONS: Fixed-bearing UKA for medial compartmental knee osteoarthritis could obtain short-term clinical results for shorter hospital stay, less complications. with fewer complication and fast recovery.

[Clinical outcome of enhanced recovery after surgery for hemiarthroplasty for the treatment of femoral neck fractures in elderly patients].

OBJECTIVE: To analyze and evaluate the clinical outcomes of enhanced recovery after surgery(ERAS) for hemiarthroplasty for the treatment of femoral neck fractures in elderly patients. METHODS: From January 2015 to December 2016, 466 patients with femoral neck fractures were admitted in our department. Among them, 154 patients were more than 80 years old, with an average age of (83.9±3.2) years old (ranged, 80 to 96 years old), including 27 males and 127 females. According to Garden classification system, 68 cases were type III and others were type IV. ERAS for hemiarthroplasty were performed for all the patients. The time before operation, blood transfusion rate, complications rate, lenth of stay and Harris score system were evaluated. RESULTS: Among 154 patients, 142 patients were followed up, with an average duration of 24.6 months(ranged, 14 to 38 months). Thirty-two patients (20.8%) completed the operation within 48 hours after admission, 67 patients(43.5%) completed the operation within 72 hours after admission, 76 patients(49.4%) discharged within 48 hours after operation, and the blood transfusion rate was 15.9%. One patient was re-hospitalized because of prosthetic dislocation. The re-hospitalization rate was 0.6%. No other patients were re-hospitalized because of superficial or deep infection or periprosthetic fracture. At the latest follow-up, the Harris hip score was 90.2±7.1, 106 patients got an excellent result, 23 good and 9 fair. CONCLUSIONS: ERAS for hemiarthroplasty can effectively shorten hospitalization time, relieve pain, reduce blood transfusion rate, reduce postoperative complications, and do not increase the readmission rate of elderly patients with femoral neck fracture, which can achieve good clinical efficacy.

Biomechanical Analysis of a Novel Intercalary Prosthesis for Humeral Diaphyseal Segmental Defect Reconstruction.

OBJECTIVE: To study the biomechanical properties of a novel modular intercalary prosthesis for humeral diaphyseal segmental defect reconstruction, to establish valid finite element humerus and prosthesis models, and to analyze the biomechanical differences in modular intercalary prostheses with or without plate fixation. METHODS: Three groups were set up to compare the performance of the prosthesis: intact humerus, humerus-prosthesis and humerus-prosthesis-plate. The models of the three groups were transferred to finite element software. Boundary conditions, material properties, and mesh generation were set up for both the prosthesis and the humerus. In addition, 100 N or 2 N.m torsion was loaded to the elbow joint surface with the glenohumeral joint surface fixed. Humeral finite element models were established according to CT scans of the cadaveric bone; reverse engineering software Geomagic was used in this procedure. Components of prosthetic models were established using 3-D modeling software Solidworks. To verify the finite element models, the in vitro tests were simulated using a mechanical testing machine (Bionix; MTS Systems Corporation, USA). Starting with a 50 N preload, the specimen was subjected to 5 times tensile (300 N) and torsional (5 N.m) strength; interval time was 30 min to allow full recovery for the next specimen load. Axial tensile and torsional loads were applied to the elbow joint surface to simulate lifting heavy objects or twisting something, with the glenohumeral joint surface fixed. RESULTS: Stress distribution on the humerus did not change its tendency notably after reconstruction by intercalary prosthesis whether with or without a plate. The special design which included a plate and prosthesis effectively diminished stress on the stem where aseptic loosening often takes place. Stress distribution major concentrate upon two stems without plate addition, maximum stress on proximal and distal stem respectively diminish 27.37% and 13.23% under tension, 10.66% and 11.16% under torsion after plate allied. CONCLUSION: The novel intercalary prosthesis has excellent ability to reconstruct humeral diaphyseal defects. The accessory fixation system, which included a plate and prosthesis, improved the rigidity of anti-tension and anti-torsion, and diminished the risk of prosthetic loosening and dislocation. A finite element analysis is a kind of convenient and practicable method to be used as the confirmation of experimental biomechanics study.

[Short-term effectiveness of total hip arthroplasty for post-traumatic osteoarthritis secondary to acetabular fracture].

OBJECTIVE: To discuss the short-term effectiveness of total hip arthroplasty (THA) for post-traumatic osteoarthritis secondary to acetabular fracture. METHODS: Between January 2004 and March 2012, the clinical data was analyzed retrospectively from 12 cases (13 hips) of post-traumatic osteoarthritis secondary to acetabular fracture undergoing THA. Of 12 patients, 6 were male and 6 were female, with an average age of 55.6 years (range, 40-68 years). The locations were the left hip in 5 cases, the right hip in 6 cases, and bilateral hips in 1 case. The interval between acetabular fracture and THA was 65.7 months on average (range, 12-240 months). The preoperative hip Harris score was 48.8 +/- 9.5. RESULTS: The incisions healed by first intention. No deep vein thrombosis and infection occurred postoperatively. Ten cases were followed up 1-7 years (mean, 4.8 years). The hip Harris score was 86.5 +/- 8.6 at last follow-up, showing significant difference when compared with preoperative score (t = 10.520, P = 0.006). X-ray films showed no acetabular prosthesis instability. Stem subsidence (2 mm) occurred in 1 case, peri-prosthetic osteolysis in 2 cases, and heterotopic ossification in 2 cases (Brooker type I and type II in 1 case, respectively). CONCLUSION: THA has satisfactory short-term effectiveness for post-traumatic osteoarthritis secondary to acetabular fracture. The good effectiveness is based on strict case selection, pathological evaluation, and the proper acetabular reconstruction.

[Evaluation of early clinical results of two stage hip replacement after failed internal fixation for femoral neck fractures].

OBJECTIVE: To evaluate the early clinical results of two stage hip replacement after failed internal fixation for femoral neck fractures in young patients. METHODS: From June 2008 to June 2010,24 patients with femoral head necrosis caused by failed internal fixation were treated with hip arthroplasty. Among them, 12 patients were male and 12 patients were female, with an average age of 42.9 years old (ranged, 18 to 58). According to Harris score and X-ray examination, the clinical result was evaluated. RESULTS: Twenty-three cases were followed up with an average age of 34.4 months (ranged, 25 to 48). After operation, 1 case complicated with the dislocation of hip joint. No deep infection of hip joint, prosthetic loosing or peripheral fracture was found. The mean Harris score was 90.9 +/- 4.3, and 18 obtained excellent results, 4 good and 1 fair. CONCLUSION: Although treatment of femoral head necrosis with two stage hip replacement after failed internal fixation is difficult during operation, its early result is satisfactory.