The use of bovine-derived hydroxyapatite xenograft for defect filling in opening-wedge high tibial osteotomy.

High tibial osteotomy is a reliable procedure for the correction of knee varus deformity. An opening-wedge high tibial osteotomy (OW-HTO) is the most popular technique. The results of the bone defect after opening the wedge needed special treatment to ensure bone healing. This study aims to evaluate the use of bovine-derived hydroxyapatite graft for defect filling after OW-HTO. Methods: A retrospective study was performed on all patients who received OW-HTO at Prof. Dr R. Soeharso Orthopaedic Hospital from November 2019 to December 2022. A total of 21 patients (24 knees) were included in this study. Clinical dan radiological evaluation was performed on all patients preoperative and postoperatively. The mean of the follow-up period was 12.6 months with a minimum of 4 months follow-up. Results: Primary medial uni-compartment knee osteoarthritis was the most common diagnosis, with 17 of 24 cases (70.8%). Mechanical axis deviation was changed from 31 mm medial deviation (range: 8-52 mm) to 0.45 mm medial deviation (range: 13 - (-8) mm). The anatomic tibiofemoral angle was corrected from a preoperative mean of 4.7° of varus to a mean of 5.8° of valgus postoperatively. Bone defect height was mean 15.9 mm with a range of 10-23 mm. Bone defect width was mean 46.7 mm (range: 34-60 mm). Hydroxyapatite graft integration with the host bone was found in all patients during the final follow-up period. Conclusions: Bovine-derived hydroxyapatite graft is a safe and effective material for bone defect filling in OW-HTO procedures with a high bone union rate.

Asymmetric bilateral traumatic hip dislocation: Report of two cases.

INTRODUCTION AND IMPORTANCE: Asymmetric bilateral hip dislocation is an extremely rare condition. The mechanism of injury and severity are variables. We reported two cases of asymmetric bilateral hip dislocation with different pattern of injury and different onset of injury. CASE PRESENTATION: The first case was a male 20 years old with 7 months neglected asymmetric bilateral hip dislocation. Total hip arthroplasty (THA) was performed on both hips, which resulted in good clinical outcomes. The second case was a male 32 years old with acute right open anterior dislocation (obturator type) and left posterior fracture-dislocation. Emergency debridement and open reduction were performed on the patients with reduction and fixation for the left hip. CLINICAL CASE DISCUSSION: To the best of our knowledge, this is the first reported case of open anterior hip dislocation with exposed femoral head on inguinal area in the setting of asymmetric bilateral hip dislocation. Furthermore, this article also presented another case with >6 months neglected time along with the surgical treatment. CONCLUSIONS: Asymmetric bilateral hip dislocation is a rare injury which usually associated with high-energy trauma. Open injury with the exposed femoral head is possible to occur in this kind of rare case. In the setting of long-term neglected cases, total hip arthroplasty could be recommended as the treatment choice.

Mechanoreceptor analysis on femoral and tibial site remnant of anterior cruciate ligament injury using immunohistochemistry.

Introductions: More than 50% of knee ligament injuries are anterior cruciate ligament (ACL) injuries. The injury can lead to instability and osteochondral damage which in turn leads to early osteoarthritis. ACL remnant contains sensory nerve cells and mechanoreceptors which are useful for reinnervation of the graft and maintaining the knee stability. However, ACL remnant preservation can interfere the visualization during surgery. The number of mechanoreceptors in the ACL remnant of the tibia and femur have to be determined to help the surgeon get better visualization and at the same time preserve the mechanoreceptors in the ACL remnant during reconstruction. Methods: This study aims to evaluate semi-quantitatively the expression of mechanoreceptors in ACL remnant in the tibia and femur using immunohistochemistry. From January to April 2021, 10 femoral and 10 tibial remnants was obtained from ACL injury patient who received arthroscopic ACL reconstruction. Both of them were analysed using immunohistochemistry with S100 and NFL antibodies. The type of remnant was recorded and the expression of the mechanoreceptor was observed under the microscope. Results: The most common type of ACL remnant recorded were type 2 (50%), followed by type 1 (40%) and type 4 (10%). There were no significant differences in the expression of mechanoreceptors between femoral remnant and tibial remnant (p = 0.45 and p = 0.134). Conclusions: No difference in the expression of mechanoreceptors of femoral and tibial ACL remnant. Preservation of both femoral and tibial remnants is important in ACL reconstruction surgery.

Prosthetic joint infection of the hip and knee due to Mycobacterium species: A systematic review.

BACKGROUND: Mycobacterium species (Mycobacterium sp) is an emerging cause of hip and knee prosthetic joint infection (PJI), and different species of this organism may be responsible for the same. AIM: To evaluate the profile of hip and knee Mycobacterium PJI cases as published in the past 30 years. METHODS: A literature search was performed in PubMed using the MeSH terms "Prosthesis joint infection" AND "Mycobacterium" for studies with publication dates from January 1, 1990, to May 30, 2021. To avoid missing any study, another search was performed with the terms "Arthroplasty infection" AND "Mycobacterium" in the same period as the previous search. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses chart was used to evaluate the included studies for further review. In total, 51 studies were included for further evaluation of the cases, type of pathogen, and treatment of PJI caused by Mycobacterium sp. RESULTS: Seventeen identified Mycobacterium sp were reportedly responsible for hip/knee PJI in 115 hip/knee PJI cases, whereas in two cases there was no mention of any specific Mycobacterium sp. Mycobacterium tuberculosis (M. tuberculosis) was detected in 50/115 (43.3%) of the cases. Nontuberculous mycobacteria (NTM) included M. fortuitum (26/115, 22.6%), M. abscessus (10/115, 8.6%), M. chelonae (8/115, 6.9%), and M. bovis (8/115, 6.9%). Majority of the cases (82/114, 71.9%) had an onset of infection > 3 mo after the index surgery, while in 24.6% (28/114) the disease had an onset in ≤ 3 mo. Incidental intraoperative PJI diagnosis was made in 4 cases (3.5%). Overall, prosthesis removal was needed in 77.8% (84/108) of the cases to treat the infection. Overall infection rate was controlled in 88/102 (86.3%) patients with Mycobacterium PJI. Persistent infection occurred in 10/108 (9.8%) patients, while 4/108 (3.9%) patients died due to the infection. CONCLUSION: At least 17 Mycobacterium sp can be responsible for hip/knee PJI. Although M. tuberculosis is the most common causal pathogen, NTM should be considered as an emerging cause of hip/knee PJI.

New acetabulum bone formation after 10-years impaction bone graft and cemented acetabular cup lead to simple revision-THA with cementless acetabular cup: A case report.

BACKGROUND: Secondary hip osteoarthritis with acetabular bone defect is still a challenging case in hip arthroplasty surgery. The incidence of revision total hip arthroplasty is estimated to be between 10% and 15% in 10 years. Simple revision cementless acetabular cup after a prior complex cemented-THA rarely performed. CASE PRESENTATION: A case of aseptic loosening with prosthesis dislocation after THA was reported in a 54 year-old female patient. The patient had prior surgery of THA 10 years ago due to secondary post-traumatic hip osteoarthritis with acetabular bone defect. At the first surgery, cemented acetabular cup with acetabular bone grafting was performed to fill the defect. A complete new acetabulum bone formation was encountered at 10 years after the surgery which lead to simple revision THA with primary cementless acetabular cup. Excellent functional outcome was also reported at the final follow-up after revision THA. CONCLUSION: This case showed that the potential of bone healing of the acetabulum cannot be underestimated. Therefore, it is suggested to always put an adequate bone graft to manage acetabular bone defect in THA surgery and a new acetabulum bone formation can be expected.

Both medial and lateral bucket-handle meniscus tears associated with chronic ACL injury: A rare presentation of triple-PCL sign.

BACKGROUND: Several types of meniscal tear could be presented in both acute and chronic anterior cruciate ligament injury. The incidence of bucket-handle meniscus tears can be up to 30% of the overall meniscus tears cases. The case of both compartment (medial and lateral) bucket-handle meniscus is rarely occurred. CASE: A case of both medial and lateral bucket-handle meniscus tears was reported in a male of 21 years old. The patient also had a chronic anterior cruciate ligament injury. The magnetic resonance imaging also showed a rare presentation of the triple-PCL sign with the sagittal view. Arthroscopic surgery with a meniscus repair and anterior cruciate ligament reconstruction was performed on the patient. CONCLUSIONS: Several specific imaging signs including triple-PCL sign could be presented in a rare case of both medial and lateral bucket-handle meniscus tears. Recognition of this sign is important to have accurate preoperative diagnosis and proper treatment plan.

Acute-shortening and re-lengthening (ASRL) procedure with monorail fixator to treat femur/tibia nonunion: A retrospective study.

BACKGROUND: The distraction osteogenesis procedure has a high potential to treat bone defect problems. The alternative technique to treat nonunion associated with a bone defect is the acute shortening and re-lengthening (ASRL) procedure. This study aimed to evaluate the outcome of ASRL procedure with a monorail fixator to treat femur/tibia nonunion associated with the bone defect. METHOD: Retrospective analysis was performed to patients who received ASRL procedure with monorail fixator for femur or tibia nonunion from October 2018 to October 2020 at Prof. Dr. R. Soeharso Orthopaedic hospital. One case was loss to follow-up and excluded from the study. The rest of 16 cases were included for further analysis. The evaluation was performed to the demographic, intraoperative procedure, problems/complications, additional procedure, and final outcome. RESULTS: There were 13 male and three female patients with age ranged from 16 to 64 years old. The follow-up period ranges 9-31 months. ASRL procedures performed to 6 femur and 10 tibias. The problems/complications: two cases with problems associated with callus formation, two cases of fracture at corticotomy site, one case of skin necrosis, one case of osteomyelitis, one case of malrotation. Additional surgical procedures were needed 5/16 (31.2%) cases. Evaluation at the final follow-up period showed 14/16 (87.5%) cases had a complete bone union. CONCLUSIONS: Acute shortening and re-lengthening (ASRL) could be reliable as a method of treatment for femur/tibia nonunion associated with the bone defect. Several possible complications need to be considered prior to perform this procedure.

Surgical Management of Macrodystrophia Lipomatosa, a rare case report of the left hand middle finger macrodactyly.

INTRODUCTION: Macrodystrophia Lipomatosa is a rare congenital non-hereditary disorder, characterized by the presence of gigantism of a small part of the limb or the whole limb due to an overgrowth and disproportionate growth of fibroadipose tissue, causing macrodactyly. CASE PRESENTATION: One case of the 14-year-old girl presented with an enlarged middle finger of her left hand since birth, discomfort during the last 6 months, and resistance to flex, was underwent surgery by performing debulking procedure and a yellow cord-like mass was obtained from the digital nerve covered and enlarged by fibrofatty tissue to the palm area, could be cut off completely. Imaging and histopathological examination revealed to macrodystrophia lipomatosa. We follow up the patient for the finger's range of motion, the neurological disturbance and re-enlargement of the tumor. DISCUSSION: Since there were compression of the nerves, functional impairment due to enlarge fingers and cosmesis problems, the surgery was indicated. Types of surgery may include debulking of soft tissue, especially adipose tissue. The mass size was decrease, motor function and movement of the middle finger were normal post operatively, but sensory deficits persisted according to the distribution of the digital nerves. Three months and six years after surgery, no enlargement of the middle finger, normal motor function, normal finger movements but sensory deficit still persisted according to the distribution of the digital nerves. CONCLUSION: Surgical management in macrodactyly due to macrodystrophia lipomatosa of the finger give the satisfactory result.

Distraction osteogenesis at the site of previously cystic bone lesion of femur: A case report.

INTRODUCTION AND IMPORTANCE: Limb length discrepancy can be occurred as residual problems after bone cyst treatment. Distraction osteogenesis is one of surgical option to treat this problem. CASE PRESENTATION: A male 27 years old came with 3 cm residual lower limb discrepancy after treatment of femoral aneurismal bone cyst (ABC). Distraction osteogenesis has been successfully performed to treat this case at the site of previously cystic bone lesion. CONCLUSION: Good quality of callus could be expected at the site of distraction osteogenesis that previously a cystic bone lesion.

A decade of evolution in Indonesian orthopedic publication: A bibliographic report.

During the past decade, there was an increasing interest in orthopedic research in Indonesia. Therefore we aimed to investigate the profile of Indonesian orthopedic trend publication from 2010 to 2019. Systematic research was conducted to identify all orthopedic articles authored by Indonesian orthopedic surgeons. Article details (number of authors, authors' affiliation, publishing journal), type of author's affiliation, affiliate collaboration, study field, type, and level of evidence (LOE) were recorded and evaluated. Publishing journal metric and author h-index were also recorded. Descriptive statistics were used to summarize the data. Two hundred and twenty articles were included in our study. Clinical studies were the most common article type, followed by case reports and basic science. Among clinical articles, therapeutic studies were found significantly more frequent. On the other hand, economic studies were not found in this study period. The most popular field was oncology, followed by knee and spine. The average number of authors per article was 5.23 with a total of 205 individuals who had contributed during this decade. University hospital was the most common affiliation found and single-center study was the most common affiliate collaboration. The most common level of evidence was level V (case reports). Eighty-seven specific publishing journals were identified. More than 42% of the articles were published in journals with SJR between 0.25 and 0.50. The average author h-index was 3.56 (0-7). Although there was an increasing trend and quantity of publications among Indonesian authors, most articles had level 5 evidence (case reports) and the quality of publishing journals was mostly Q3 with a low-moderate SJR. Improvement of the article's quality and institutional collaboration will be needed for future contribution in global orthopedic society.

Survival and Risk Factor Analysis of Medial Open Wedge High Tibial Osteotomy for Unicompartment Knee Osteoarthritis.

PURPOSE: The purpose of this retrospective study was to evaluate the survival rates and analyze the factors that affect survival rate after primary treatment with medial open wedge high tibial osteotomy (MOWHTO) for medial unicompartmental knee osteoarthritis. METHODS: Clinical evaluation using Knee Society Score (KSS) and Western Ontario and McMaster Universities Osteoarthritis Index score and radiographic evaluation, including mechanical axis, were done before and after surgery. The main failure criteria for survival included the conversion to total knee arthroplasty or KSS of <60 points. Furthermore, risk factors that affected the survival after MOWHTO were analyzed. RESULTS: Three hundred thirty-nine knees were included after a minimum of 5 years' follow-up. Their mean age was 56 years, and mean follow-up duration was 9.6 years. The mean KSS and Western Ontario and McMaster Universities Osteoarthritis Index scores were significantly improved after surgery (87.3 and 18.5 points at 5 years and 81.7 and 23.6 points at 10 years). The mean hip-knee-ankle (HKA) angle was corrected from 7.2° varus to 3.4° valgus 1 year after surgery, which was maintained until 10 years after surgery (2.9° valgus at 5 years and 2.3° valgus at 10 years, P > .05). Using Kaplan-Meier survival estimates, the probability of survival for MOWHTO was 96.8% at 5 years, 87.1% at 10 years, and 85.3% at 13 years. The multivariate regression analysis revealed that age ≥65 years (hazard ratio [HR] = 2.34, P = .046), medial compartment cartilage damage International Cartilage Repair Society grade ≥4 (HR = 2.46, I = .045), lateral compartment cartilage damage International Cartilage Repair Society grade≥2 (HR = 3.38, P = .006), postoperative HKA angle <0° (HR = 4.69, P < .001) were associated with failure. CONCLUSION: MOWHTO seems to be a good treatment option for young and active patients with medial knee osteoarthrosis and varus alignment, with acceptable survival rates and satisfactory outcomes. Age ≥65 years, grade 4 cartilage damage in medial compartment, grade ≥2 cartilage damage in lateral compartment, and undercorrection of HKA angle appear to be significant risk factors associated with failure. LEVEL OF EVIDENCE: Level IV: retrospective case series.

Research on the Anterolateral Ligament of the Knee: An Evaluation of PubMed Articles From 2010 to 2019.

BACKGROUND: The anterolateral ligament (ALL) of the knee remains a topic of interest. All aspects of the ligament, including its anatomy, biomechanics, imaging, and clinical importance, are areas for research among knee surgeons. PURPOSE: To evaluate the trends in research on the ALL of the knee, as indicated by studies indexed in PubMed from 2010 to 2019. STUDY DESIGN: Cross-sectional study. METHODS: We searched PubMed for article titles from January 1, 2010, to December 31, 2019, that included the term "anterolateral ligament." The initial search was performed with the terms "anterolateral ligament AND knee" and "anterolateral ligament NOT knee." Next, we performed a search using "anterolateral complex OR anterolateral reconstruction OR lateral extra-articular tenodesis" to avoid missing any studies. A bibliometric evaluation was performed for the search results, and we noted the characteristics of the most cited articles in PubMed. RESULTS: Published studies on the ALL peaked in 2017, with 56 studies, and then declined from 2017 to 2019. The 3 leading journals with articles on the ALL were Arthroscopy; Knee Surgery, Sports Traumatology, Arthroscopy; and The American Journal of Sports Medicine. Cadaveric anatomic, cadaveric biomechanical, and clinical imaging studies of the ALL were the most common types of studies published from 2010 to 2019. Clinical studies on the ALL consisted of 18 articles, with the majority displaying a low level of evidence. CONCLUSION: Cadaveric anatomic/histological, cadaveric biomechanical, and clinical imaging studies of the ALL were the most commonly published studies from 2010 to 2019. More clinical outcome studies with a high level of evidence are needed to increase the supporting data for the future practice of ALL reconstruction.

Primary repair for injury of medial collateral ligament during total-knee arthroplasty.

The aim of this study was to determine whether primary repair for intraoperative injury of the medial collateral ligament (MCL) can achieve satisfactory clinical results when compared to the clinical results of patients with no MCL injury. Simultaneously, we sought to determine the differences between 2 methods of primary repair (anchor suture and staple) in terms of their clinical outcomes.In our institute, 3897 total-knee arthroplasties (TKAs) were performed between 2003 and 2014. Sixty-five patients who suffered an MCL injury during the TKA procedure and in whom the injury was repaired with a suture anchor or staple (suture anchor: 36 vs staple: 29) were studied. A matched group of 65 patients without an MCL injury was selected to serve as the control group. Subjective feelings of instability and functional outcomes were assessed using the knee society (KS) score and the Western Ontario & McMaster Universities Osteoarthritis Index (WOMAC). Objective stability was evaluated by the measurement of opening angles in extension and at 30° of knee flexion on valgus stress radiographs. The clinical outcomes and stability results were compared between the suture anchor and staple methods.The KS and WOMAC scores in patients who received primary repair of MCL injury during TKA improved from 50.6 ±â€Š13.1 to 87.3 ±â€Š7.3 (P < .001) and 65.9 ±â€Š14.4 to 17.7 ±â€Š6.6 (P < .001), respectively. However, there were no statistically significant differences in the KS (P = .84) and WOMAC (P = .71) scores when comparing the group that received primary repair to the control group. Radiographic stability also showed no differences between the repair and control groups in extension and at 30° of flexion (P = .48 and P = .11, respectively). In the subgroups, there were no significant differences between the suture anchor and staple repair methods in terms of stability and clinical outcomes.Primary repair of an MCL injury during TKA may have clinical outcomes comparable to that in the no MCL injury group. Both staple and suture anchor repair methods could provide excellent clinical and stability outcomes in these types of cases, although a further cohort study is required to validate our results.

Comparison of Intermediate-term Outcomes of Total Ankle Arthroplasty in Primary and Ligamentous Post-traumatic Osteoarthritis.

BACKGROUND: Ankle ligamentous injuries without fracture can result in end-stage ligamentous post-traumatic osteoarthritis, which may cause ligamentous imbalance after total ankle arthroplasty (TAA). However, outcomes of TAA in these patients are not well known. The purpose of this study was to evaluate intermediate-term clinical and radiographic outcomes of TAA in patients with ligamentous post-traumatic osteoarthritis and compare them with results of TAA for patients with primary osteoarthritis. METHODS: We enrolled 114 patients (119 ankles) with consecutive primary TAA using HINTEGRA prosthesis at a mean follow-up duration of 6.0 years (range, 3-13). We divided all patients into 2 groups according to the etiology of osteoarthritis: (1) primary osteoarthritis group (69 ankles) and (2) ligamentous post-traumatic osteoarthritis group (50 ankles). RESULTS: There was no significant intergroup difference in mean Ankle Osteoarthritis Scale (AOS), American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score, Short Form-36 Physical Component Summary, visual analog scale pain score, ankle range of motion, or complications at the final follow-up. However, the final tibiotalar angle was less corrected to 4.2 degrees in the ligamentous post-traumatic osteoarthritis group compared to 2.7 degrees in the primary osteoarthritis group (P = .001). More concomitant procedures were required at the index surgery for the ligamentous post-traumatic osteoarthritis group (P = .001). The estimated 5-year survivorship was 93.4% (primary osteoarthritis group: 91.3%; ligamentous post-traumatic osteoarthritis group: 95.8%). CONCLUSIONS: Clinical outcomes, complication rate, and 5-year survivorship of TAA in ankles with primary and ligamentous post-traumatic osteoarthritis were comparable with intermediate-term follow-up. Our results suggest that TAA would be a reliable treatment in ankles with ligamentous post-traumatic osteoarthritis when neutrally aligned stable ankles are achieved postoperatively. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

An Unusual Case of Anteriorly Displaced Posterior Cruciate Ligament Tibial Attachment Avulsion Injury.

BACKGROUND: Avulsion injury to the tibial attachment of posterior cruciate ligament (PCL) is frequently occur. The purpose of this report is to highlight an unusual variation of PCL avulsion injury. CASE PRESENTATION: A 24-year-old female was suffered a motorcycle accident 1 day before admission. The patient complained of severe right knee pain. Plain radiograph and CT-scan revealed an anteriorly displaced tibial attachment PCL avulsion fracture. Open surgical fixation was done to the patient. A satisfactory outcome was observed until the final 1-year follow-up. CONCLUSIONS: The bony fragment of the tibial attachment of posterior cruciate ligament avulsion injury can be displaced to the anterior compartment of the knee. Concomitant injury to other knee structures should be suspected when finding this case. Special consideration is also needed during the management of this unusual case.

Two-stage revision for periprosthetic joint infection of the hip: Culture-negative versus culture-positive infection.

INTRODUCTION: Negative culture findings are common in periprosthetic joint infection (PJI) of the hip. METHODS: Retrospective study was performed to total 84 patients which devided into two groups: culture-negative (n: 27) and culture-positive (n: 57). RESULTS: The reimplantation rate was 96.3% and 91.2% in the culture-negative and culture-positive groups, respectively. The overall infection control rate was 92.6% and 82.4% in the culture-negative and culture-positive groups, respectively. CONCLUSION: Two-stage revision resulted a comparable outcome for the treatment of culture-negative periprosthetic joint infection of the hip compared to the culture-positive group.

Initial Response of Human Bone Marrow-Derived Stem Cells after Contact with Ultrahigh-Molecular-Weight Polyethylene (UHMWPE) Material: An In Vitro Study on Cell Viability and Interleukin-6 Expression.

INTRODUCTION: Ultrahigh-molecular-weight polyethylene (UHMWPE) is a thermoplastic polymer useful in biomaterial applications, especially in orthopedic field. Yet, little is known concerning its initial effect on human bone marrow stem cells (hBMSCs) after implantation. MATERIALS AND METHODS: A cytotoxicity analysis was performed with a 3-(4,5-dimethylthiazol 2-yl)-2,5-diphenyltetrazolium assay after 24, 48, and 72h of incubation of hBMSC culture. Expression of interleukin-6 (IL-6) was measured using enzyme-linked immunosorbent assay. Cell viability was measured with Inhibitory concentration 50% (IC50) formula. RESULTS: All treatment groups showed a cell viability of >50% ranging from 78% to >100%. Lower expression of IL-6 of hBMSC compared to control group was found in 48h of incubation period. CONCLUSION: hBMSC showed high cell viability after initial contact with UHMWPE material. Modulation of IL-6 expression was present at the initial stage as a response to foreign material.

Treatment outcome of dome osteotomy of the pelvis combined with trochanteric advancement for sequelae of Perthes' disease.

OBJECTIVE: Disparity in size between femoral head and acetabulum could promote premature degeneration of the hip joint. The purpose of this study was to report the results of Kawamura's dome osteotomy for acetabular dysplasia due to sequelae of Perthes' disease. PATIENTS AND METHODS: Fourteen patients (14 hips) operated between 1999 and 2012 were retrospectively reviewed. There were 9 males and 5 females with a mean age of 29 years (range, 15-54 years). Functional and radiological results were reviewed at mean follow-up of 9 years (range, 4-12 years). RESULTS: Pain relief was obtained in 13 of 14 (92.8%) patients postoperatively. Good to excellent functional outcome was obtained in 10 of 14 (71.4%) patients. Mean Harris hip score was improved from 63 to 84 (p < 0.05) at the final follow-up. Improvement of limping gait was observed in 10 of 14 (71.4%) patients. Center edge angle improved from mean 24° (11-36°) preoperatively to mean 35° (27-46°) postoperatively (p < 0.05), acetabular angle improved from mean 43° (36-49°) preoperatively to mean 37° (32-44°) postoperatively (p < 0.05), acetabular head index improved from mean 69% (50-83%) preoperatively to mean 85% (73-100%) postoperatively (p < 0.05). Progression of arthrosis stage occurred in 3 of 14 (21%) patients. None of the hip with preoperative Stulberg III, 2 of 9 hips with Stulberg IV and 2 of 2 hips with Stulberg V needed conversion to total hip arthroplasty during the follow-up. CONCLUSION: Dome osteotomy of the pelvis combined with trochanteric advancement could give a reasonable treatment outcome for acetabular dysplasia due to Perthes' disease at mid to long-term follow-up. Advanced stage of arthrosis, preoperative Stulberg V and no improvement of limping gait after the surgery possibly associated with poor outcome. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Breakage of the Tail Portion of the Lag Screw during Removal of Proximal Femoral Zimmer Natural Nail: Report of Two Cases with Technical Notes.

Proximal femoral cephalomedullary nailing is one of the treatments of choice for intertrochanteric fracture. Zimmer Natural Nail® (ZNN; Zimmer) is one of the alternatives. We report two cases of broken tail portion of the ZNN lag screw during the removal procedure. This may be the first reported cases in scientific literature with this pattern of failure. We report these cases to highlight one of the possible problems that could occur during removal of this implant which can possibly prolong the operation time significantly if the required device is not prepared.