Sexual dimorphism of the posterior condylar offset of the femur and the medial posterior slope of the tibia in non-arthritic knees of Egyptian adults: an MRI study.

BACKGROUND: The aim of this magnetic resonance imaging (MRI) study was to investigate controversial sexual dimorphism of the posterior condylar offset of the femur (the offset) and the posterior slope of the tibia (the slope) in non-arthritic knees of Egyptian adults. METHODS: On 100 male and 100 female MRIs of non-arthritic knees, linear measurements of the distal part of the femur (the offset) and the angular measurements of the proximal part of the tibia (the slope) were performed and compared regarding sex and ethnicity. The intraclass correlation coefficient (ICC) was used to test the interrater agreement. RESULTS: Both offsets and the lateral offset ratio were larger in males (p < 0.001), the medial offset ratio, and the medial slope in females (p from < 0.001 to 0.007), whereas the lateral slope was sex-free (p = 0.41). Irrespective of sex, however, the medial offset with its ratio, and the medial slope were larger than their counterparts (p < 0.001). Our means of the offsets, their ratios, and the slopes mostly differed from those of other ethnicities (p from ≤ 0.001 to 0.004). ICCs > 0.8 proved MRI's precision was high. CONCLUSION: There was a sexual dimorphism of both the offset and the medial slope in non-arthritic knees of Egyptian adults. We believe future designs of knee implants should consider these differences in order to improve postoperative range of motion and patients' satisfaction after total knee arthroplasty. Level of evidence Level III Retrospective Cohort Study. Trial registration ClinicalTrials.gov identifier: NCT03622034, registered on July 28, 2018.

Preoperative stiffness is the most important predictor of postoperative patient's satisfaction after total knee arthroplasty.

PURPOSE: To predict the most important preoperative factor affecting the patient satisfaction after total knee arthroplasty (TKA) in trial to improve patient counselling process. METHODS: We retrospectively reviewed all patients who underwent primary TKA from January 1, 2018, to January 31, 2019, with minimum one-year follow-up for the previously collected patient-reported outcome measures (PROMs) as Oxford Knee Score (OKS) and Knee Injury and Osteoarthritis Outcome Score for joint replacement (KOOS, JR) preoperative, 6 months and 12 months postoperative. RESULTS: By using Oxford knee score at 12 months as dependent variable, we found a negative moderate spearman correlation between age and Oxford knee score at 12 months postoperative. Moderate negative spearman correlation was also found between Oxford knee score at 12 months postoperative and KOOS pain, stiffness and function scores at preoperative and 6 months postoperative, denoting higher satisfaction at 12 months with less perceived stiffness, pain and limited function at baseline and 6 months postoperative. A multivariate regression analysis was done using the oxford knee score at 12 months as dependent variable to detect the predictors of oxford knee score at 12 months postoperatively and showed that younger age and less perception of stiffness at baseline were significant predictors of higher Oxford knee score: higher satisfaction at 12 months postoperative. CONCLUSION: Preoperative stiffness can predict the postoperative satisfaction score more than any other factor. We also address the importance of combining more than one PROM in assessing patients as OKS and KOOS, JR.

Debridement, Antibiotics, and Implant Retention for an Early Periprosthetic Infection After Unicompartmental Knee Arthroplasty: A Technical Note.

Early periprosthetic joint infection in unicompartmental knee arthroplasty (UKA) is shown to have a detrimental effect on the success of UKA surgery not only because of the sequences of the infection but also due to the other healthy lateral compartment. It is well known that Oxford meniscal bearing UKA is a very precise procedure that the use of any excessive force may have an injurious effect on the future prosthesis stability with a higher risk of bearing dislocation. This technical note aims at describing how to deal with a case of early periprosthetic joint infection in a female patient who underwent debridement, wash, implant retention and change of the mobile bearing insert including the demonstration of a difficult step during this procedure.

Anthropometric measurements of non-arthritic knees in an Egyptian population: an MRI-based study.

BACKGROUND: Knee anthropometric characteristics were evaluated for different ethnicities; however, data from North African populations are deficient. The primary aim was to investigate the Egyptian knees' anthropometric characteristics as a representative of North African populations. Secondary aims are as follows: (1) to study the anthropometric gender difference, (2) to compare results with other ethnic groups, and (3) to study the mismatch in comparison to geometric characteristics of modern TKA implant designs. METHODS: Two hundred normal knee MRI scans (100 females and 100 males, aging from 18 to 60) were obtained for analysis. Linear measurements (anteroposterior (AP), mediolateral (ML), and aspect ratio (AR)) of the planned cut surface of the distal femur (f) and the proximal tibia (t) were evaluated. RESULTS: A significant difference between both sexes was found, males had larger measurements in anteroposterior [fAP: 60.97 ± 3.1 vs 54.78 ± 3.3 (P < 0.001), tAP: 46.89 ± 3.0 vs 41.35 ± 2.9 (P < 0.001)] and mediolateral [fML: 74.89 ± 3.2 vs 67.29 ± 3.7 (P < 0.001), tML: 76.01 ± 3.0 vs 67.26 ± 3.2 (P < 0.001)], the mean femoral and tibial AP and ML measurements were different from other ethnic groups. None of the seven studied TKA systems matched the largest ML or the smallest AP dimensions of the distal femur in the current study population. CONCLUSION: A significant difference was found between males' and females' knee anthropometric characteristics. Some of the commonly used TKA implants in our area could not provide a perfect fit and coverage. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03622034 , registered on July 28, 2018.

Evaluating distal femoral torsion and posterior condylar line reliability for adjusting femoral component rotation in TKA, Egyptian population radiographic study.

BACKGROUND: Femoral component rotational alignment is critical for successful TKA. The primary study objective is to measure the preoperative distal femoral torsion (DFT) of an Egyptian patient's cohort using a seated posteroanterior (PA) knee radiograph. The secondary objectives are to check the intraoperative reliability of using the posterior condylar line (PCL) as a reference for rotation and to measure postoperative component rotation using the same radiographic technique. METHODS: 100 arthritic knees, 22 males, 78 females, 95 Varus and five valgus. A long anteroposterior radiograph [Hip to knee to ankle (HKA)] for coronal alignment assessment, and the anatomical posterior condylar angle (aPCA) between the anatomical transepicondylar axis (aTEA) and the PCL was measured in the seated PA knee radiographs for evaluating the DFT and component rotation. Intraoperative rotation was adjusted to 3° external rotation to the PCL. RESULTS: HKA improved from a preoperative mean 170.4° ± 6.2 to a postoperative mean 178.3° ± 1.5 (p < 0.005). DFT was internal in all knees; the mean aPCA was -4.5 ± 2.4 (0° to -9°), femoral component rotation significantly changed to a mean aPCA of -3.6 ± 2.3 (0° to -7°) (p = 0.005). Acceptable intraoperative patellar tracking in 94%, and patellar subluxation needed a lateral retinacular release in 2% (two valgus knees). The preoperative DFT was not affected by sex or direction of coronal deformity; more external DFT noticed in severe varus deformity. CONCLUSIONS: All keens had an internal DFT not affected by sex, or coronal deformity direction. Using PCL as a guide to adjust femoral component rotation is a valid technique in our population.

Prediction of leg length change (LLC) after correcting varus and flexion deformity in patients undergoing TKA.

PURPOSE: Patients with varus and fixed flexion deformity (FFD) undergoing TKA may have a significant leg length change (LLC) after surgery. We aimed to determine the correlation between changes in HKA or FFD and leg length in patients undergoing TKA, the combined effect of coronal and sagittal plane deformity correction on LLC, and the possibility of estimating LLC mathematically. MATERIALS AND METHODS: This was a prospective radiographic evaluation of 242 knees, which had undergone primary unilateral TKA for advanced OA with varus and FFD. Full-length standing calibrated anteroposterior radiographs were used to measure the hip-knee-ankle axis (HKA) and functional leg length after adjusting for magnification. Clinical evaluation of FFD was done using a handheld goniometer. RESULTS: 224 knees (92.6%) showed increased limb length after TKA averaging 10.7 mm (SD 9.5 mm, P = .000). There was a significant correlation between the change in HKA and FFD from preoperatively to postoperatively with the amount of LLC (ρ 0.326 and 0.346, respectively, P = .000). FFD improvement from preoperatively to postoperatively was 8.1° to 1° (P = .000), respectively. A linear relationship was established between LLC and changes in HKA and FFD, where 10° improvement in HKA would result in an LLC of nearly 4 mm, and 10° improvement in FFD would result in a LLC of nearly 8 mm. CONCLUSION: LLC may be substantial after correcting varus and FFD with unilateral TKA, it correlates with the change in HKA and FFD and can be mathematically estimated. CLINICAL TRIALS . GOV IDENTIFIER: NCT03502382.

Updates in biomaterials of bearing surfaces in total hip arthroplasty.

Total hip arthroplasty (THA) is one of the most successful surgical procedures. It entails replacement of the damaged or diseased joint surface with artificial materials. Various materials had been developed and used to achieve optimal outcomes, including longer survivorship and minimal complications. The primary materials used in the manufacture of THA implants are polymers, metal alloys, and ceramics. The failures of THA mainly result from aseptic loosening due to the production of wear particles and the development of periprosthetic joint injection. A lot of advancement and introduction of new biomaterials in THA implants' armamentarium are designed to avoid the common failure mechanisms and improve the longevity of the implants. In this review, we discussed various aspects of commonly used biomaterials in THA implants, to provide some updated information.

Technical Note on Using Intraoperative Smartphone Applications to Adjust Cup Inclination Angle during Total Hip Arthroplasty (THA).

Acetabular cup optimum position is paramount for total hip arthroplasty (THA) good outcomes. Although controversial, Lewinnek proposed safe zone for cup placement still the most widely accepted target. Cup placement can be improved using specific anatomical landmarks, computer navigation system and handheld navigation devices. As using a smartphone on daily bases became popular among orthopedic surgeons, in this technical note, we describe how to use smartphone specific applications intraoperatively during total hip arthroplasty to adjust cup inclination angle, which we believe to be easy, cheap and beneficial for young less experienced surgeons.

Post-operative hip centre restoration and migration after impaction bone grafting in revision and complex primary hip arthroplasty.

INTRODUCTION/OBJECTIVES: Although impaction grafting proved efficacy in the reconstruction of acetabular defects in primary and revision hip arthroplasty, its role in large segmental defects is still debatable. Our objective is to determine hip centre restoration and last follow-up migration after acetabular reconstruction with impaction grafting in different types of acetabular defects. METHODS: This is a single-centre retrospective radiographic study of (107) total hip arthroplasty (42 primary and 65 revision) in (104) patients using impaction grafting. The available radiographs were examined for normal, preoperative, immediate postoperative, and last follow-up vertical (Y) and horizontal (X) hip centre. Maximum acetabular defect distance (MADD), presence, and size of the mesh were recorded. RESULTS: In type I and II AAOS defects, the post-operative hip centre was not significantly different from the normal hip centre on the contralateral healthy side. In type III defects, there was a significant variation between the normal hip centre and the post-operative hip centre (P value 0.034 and 0.001 for Y and X, respectively). At 44-month follow-up of 36 hips, 31 (86%) hips migrated. The mean migration ± SD was 5.72 ± 3.7, 2, 4.15 ± 1.2, and 11.26 ± 3.9 mm for types I, II, and III, respectively (P value 0.211). Hips with MADD > 15 mm, especially with large mesh sizes migrate significantly more (P value = 0.042, 0.037, and 0.039, respectively). CONCLUSION: Hip centre restoration was better, and migration was less for type I and II AAOS rather than for type III. Other options for reconstruction should be considered.

The use of pararectus approach for Type 3B Paprosky acetabular defect with intrapelvic cup migration. Case report.

CASE: A case of Type 3B Paprosky acetabular defect with intrapelvic cup migration where anterior column plating and cup extraction was done through an abdominal pararectus approach. A male patient 63 years old reported progressive pain and walking disability after five years of cementless THR for right hip AVN. CT pelvis showed loose intrapelvic migrated cup, extensive osteolytic acetabular defects, and pelvic discontinuity. Pararectus approach was used to remove the cup and the head with concomitant plating of the anterior column Conclusion: The pararectus approach is a valid option for intrapelvic cup extraction and pelvic discontinuity fixation.

All types of component malrotation affect the early patient-reported outcome measures after total knee arthroplasty.

PURPOSE: Outcomes following total knee arthroplasty (TKA), whether clinical, radiological or survival analysis, have been well-studied. Still, there are some concerns about patient satisfaction with the outcome of the surgery and factors that might contribute to a suboptimal result. This study aims to determine if there is correlation between primary TKA malalignment and early patient-reported outcome measures (PROMs). MATERIALS AND METHODS: Sixty patients, who had primary TKA and a minimum of 2 years of follow up, were recruited for a detailed clinical and radiological examination. Knee alignment was measured in the coronal, sagittal and axial planes. Normal and the outlier measurements of the patients' knees were defined and the clinical results (PROMs) compared to see if there was a statistically significant difference. RESULTS: Correlation between postoperative limb malalignment in the coronal and the sagittal planes and PROMs was not significant. Conversely, there was significant negative correlation between all types of malrotation and PROMs. CONCLUSIONS: Although malalignment has been linked to inferior outcome and implant survival, our results showed that coronal and sagittal limb malalignment has no significant effect on early PROMs. However, all types of component rotational malalignment significantly worsen early PROMs.

Accuracy of plain antero-posterior radiographic-based methods for measurement of acetabular cup version.

INTRODUCTION: Acetabular cup version is crucial for successful total hip arthroplasty (THA). Many methods have been described for measurement of cup version angle. The aim of this study is to assess the accuracy of five commonly used methods for measurement of acetabular cup version in plain antero-posterior views of the pelvis and hip. MATERIAL AND METHODS: Sixty primary THA cases were subjected postoperatively to plain A-P of the pelvis (AP-P), A-P view of the hip (AP-H), and computed tomography (CT) imaging. The acetabular cup version was measured in AP-P and AP-H by five methods (Lewinnek, Widmer, Hassan et al., Ackland et al., and Liaw et al.). These measurements were compared to the CT measurement. RESULTS: All plain X-ray methods showed no significant differences from the CT, except those of Hassan et al. in AP-H, and Widmer and Ackland et al. in AP-P. CONCLUSIONS AND RECOMMENDATIONS: For measurement of acetabular cup version angle, we recommend the use of Lewinnek and Liaw et al. methods both in AP-P and in AP-H, while Hassan et al.'s method is recommended in AP-P only, and Widmer and Ackland et al.'s methods in AP-H only.

Opening-wedge high tibial osteotomy without bone graft.

Open wedge high tibial osteotomy has become the trend for correction of varus knee deformities. The drawbacks were the need of autogenous bone graft with its associated morbidity, and later the use of bone substitutes with their cost and delayed healing. In this study, a total of 58 consecutive patients underwent high tibial osteotomy with internal fixation by wedge (toothed) plate and screws without bone graft, from 2004 to 2008. Age of the patients ranged from 24 to 65 years. There were 37 women and 21 men. The osteotomy opening size ranged from 8 to 14 mm. The mean follow-up was 38 months. The osteotomy united in all patients. Average time to union was 12.4 weeks (range 8-16 weeks). Partial loss of correction occurred in one osteotomy. There was significant difference between the healing time and the size of the osteotomy opening. The results at the final follow-up using the HSS score were excellent in 51 knees (88%) and good in seven knees (12%). Despite the routine addition of bone graft as a part of the high tibial osteotomy procedure, this study supports medial opening-wedge high tibial osteotomy up to 14 mm without bone graft or bone substitutes, which shortens the operative time and avoids unnecessary morbidity.

Total hip arthroplasty following failure of dynamic hip screw fixation of fractures of the proximal femur.

Thirty-two patients (11 male, 21 female) with a mean age of 64 years were prospectively studied after undergoing total hip replacement after failed treatment of intertrochanteric fractures. One patient had bilateral surgery. The mean time from primary surgery to the salvage arthroplasty was 15 months (range, 4 to 32 months). The mean follow-up period was 57 months (range, 30 to 108 months). Intraoperative femoral fracture occurred in one patient and postoperative dislocation in another. Three patients had deep venous thrombosis, two had gastrointestinal bleeding and one had a non fatal pulmonary embolism. At the last follow-up, we were able to review 26 patients with 27 arthroplasties; the other 6 patients had died. The majority had good pain relief and marked functional improvement. Twenty-two patients had either no or mild pain and 24 patients were able to walk freely with or without support. Almost 78% of patients had either excellent or good clinical results based on Harris hip score. Heterotopic ossification was noted in 8 hips. Total hip arthroplasty was found in this study to be an effective salvage procedure after failed treatment of intertrochanteric fracture in elderly patients.