Purpose: Acetabular and femoral offset (FO) play an important role in total hip arthroplasty (THA). The Sundsvall method has been proposed to account for both FO and cup offset in one global hip offset measurement. In this study, we examine the agreement and inter-observer reliability of the Sundsvall method of hip offset measurement. Materials and Methods: Four hundred and ninety-nine THA patients at a single tertiary academic institution were retrospectively reviewed. Preoperative hip offset was measured on anteroposterior radiographs of the pelvis on the operative and contralateral side. Hip offset was also measured postoperatively on the operative side. Hip offset was measured using the Sundsvall method as the distance between the femoral axis and midline of the pelvis at the height of the lateral most point of the greater trochanter. All measurements were completed by two raters. Intra-class correlation coefficients (ICC) and Pearson’s correlation coefficients were used to evaluate agreement and inter-observer reliability between two raters. Results: There was excellent agreement between raters for preoperative hip offset measurement with an ICC of 0.91 (confidence interval [CI] 0.90-0.93, P<0.01) and R=0.92. There was excellent agreement between raters for postoperative hip offset with an ICC of 0.93 (CI 0.92-0.94, P<0.01) and R=0.93. Conclusion This study confirms the inter-observer agreement and reliability of the Sundsvall method of hip offset measurement. With its high agreement and reliability, the Sundsvall method is an easy and reliable way to measure hip offset that can be applied in future clinical and research settings.

Purpose: Acetabular and femoral offset (FO) play an important role in total hip arthroplasty (THA). The Sundsvall method has been proposed to account for both FO and cup offset in one global hip offset measurement. In this study, we examine the agreement and inter-observer reliability of the Sundsvall method of hip offset measurement. Materials and Methods: Four hundred and ninety-nine THA patients at a single tertiary academic institution were retrospectively reviewed. Preoperative hip offset was measured on anteroposterior radiographs of the pelvis on the operative and contralateral side. Hip offset was also measured postoperatively on the operative side. Hip offset was measured using the Sundsvall method as the distance between the femoral axis and midline of the pelvis at the height of the lateral most point of the greater trochanter. All measurements were completed by two raters. Intra-class correlation coefficients (ICC) and Pearson’s correlation coefficients were used to evaluate agreement and inter-observer reliability between two raters. Results: There was excellent agreement between raters for preoperative hip offset measurement with an ICC of 0.91 (confidence interval [CI] 0.90-0.93, P<0.01) and R=0.92. There was excellent agreement between raters for postoperative hip offset with an ICC of 0.93 (CI 0.92-0.94, P<0.01) and R=0.93. Conclusion This study confirms the inter-observer agreement and reliability of the Sundsvall method of hip offset measurement. With its high agreement and reliability, the Sundsvall method is an easy and reliable way to measure hip offset that can be applied in future clinical and research settings.

Purpose: Acetabular and femoral offset (FO) play an important role in total hip arthroplasty (THA). The Sundsvall method has been proposed to account for both FO and cup offset in one global hip offset measurement. In this study, we examine the agreement and inter-observer reliability of the Sundsvall method of hip offset measurement. Materials and Methods: Four hundred and ninety-nine THA patients at a single tertiary academic institution were retrospectively reviewed. Preoperative hip offset was measured on anteroposterior radiographs of the pelvis on the operative and contralateral side. Hip offset was also measured postoperatively on the operative side. Hip offset was measured using the Sundsvall method as the distance between the femoral axis and midline of the pelvis at the height of the lateral most point of the greater trochanter. All measurements were completed by two raters. Intra-class correlation coefficients (ICC) and Pearson’s correlation coefficients were used to evaluate agreement and inter-observer reliability between two raters. Results: There was excellent agreement between raters for preoperative hip offset measurement with an ICC of 0.91 (confidence interval [CI] 0.90-0.93, P<0.01) and R=0.92. There was excellent agreement between raters for postoperative hip offset with an ICC of 0.93 (CI 0.92-0.94, P<0.01) and R=0.93. Conclusion This study confirms the inter-observer agreement and reliability of the Sundsvall method of hip offset measurement. With its high agreement and reliability, the Sundsvall method is an easy and reliable way to measure hip offset that can be applied in future clinical and research settings.

Purpose: Acetabular and femoral offset (FO) play an important role in total hip arthroplasty (THA). The Sundsvall method has been proposed to account for both FO and cup offset in one global hip offset measurement. In this study, we examine the agreement and inter-observer reliability of the Sundsvall method of hip offset measurement. Materials and Methods: Four hundred and ninety-nine THA patients at a single tertiary academic institution were retrospectively reviewed. Preoperative hip offset was measured on anteroposterior radiographs of the pelvis on the operative and contralateral side. Hip offset was also measured postoperatively on the operative side. Hip offset was measured using the Sundsvall method as the distance between the femoral axis and midline of the pelvis at the height of the lateral most point of the greater trochanter. All measurements were completed by two raters. Intra-class correlation coefficients (ICC) and Pearson’s correlation coefficients were used to evaluate agreement and inter-observer reliability between two raters. Results: There was excellent agreement between raters for preoperative hip offset measurement with an ICC of 0.91 (confidence interval [CI] 0.90-0.93, P<0.01) and R=0.92. There was excellent agreement between raters for postoperative hip offset with an ICC of 0.93 (CI 0.92-0.94, P<0.01) and R=0.93. Conclusion This study confirms the inter-observer agreement and reliability of the Sundsvall method of hip offset measurement. With its high agreement and reliability, the Sundsvall method is an easy and reliable way to measure hip offset that can be applied in future clinical and research settings.

PURPOSE: The Paprosky classification system of acetabular defects is complex and its reliability has been questioned. The purpose of this study was to evaluate the effectiveness of different radiologic imaging modalities in classifying acetabular defects in revision total hip arthroplasty (THA) and their value of at different levels of training. MATERIALS AND METHODS: Bone defects in 8 revision THAs were classified by 2 fellowship-trained adult reconstruction surgeons. A timed presentation with representative images for each case (X-ray, two-dimensional computed tomography [CT] and three-dimensional [3D] reconstructions) was shown to 35 residents from the first postgraduate year of training year of training (PGY-1 to PGY-5), 2 adult reconstruction fellows and 2 attending orthopaedic surgeons. The Paprosky classification of bone defects was recorded. The influence of image modality and level of training on classification were analyzed using chi-square analysis (alpha=0.05). RESULTS: Overall correct classification was 30%. The level of training had no influence on correct classification (P=0.531). Using X-ray led to 37% correctly identified defects, CT scans to 33% and 3D reconstructions to 20% of correct answers (P < 0.001). There was no difference in correct classification based defect type (P < 0.001). Regardless of level of training or imaging, 64% of observers recognized type 1 defects, compared to only 16% correct recognition of type 3B defects. CONCLUSION: Using plain X-rays led to an increased number of correct classification, while regular CT scan and 3D CT reconstructions did not improve accuracy. The classification system of acetabular defects can be used for treatment decisions; however, advanced imaging may not improve its utilization.
Acetabulum* ; Adult ; Arthroplasty, Replacement, Hip ; Classification ; Humans ; Internship and Residency* ; Pelvis* ; Reoperation ; Surgeons ; Tomography, X-Ray Computed