Arthroplasty for femoral neck fractures is at risk for under restoration of lateral femoral offset.

PURPOSE: The aim of the study was to determine the restoration of hip biomechanics through lateral offset, leg length, and acetabular component position when comparing non-arthroplasty surgeons (NAS) to elective arthroplasty surgeons (EAS). METHODS: 131 patients, with a femoral neck fracture treated with a THA by 7 EAS and 20 NAS, were retrospectively reviewed. 2 blinded observers measured leg-length discrepancy, femoral offset, and acetabular component position. Multivariate logistic regression models examined the association between the surgeon groups and restoration of lateral femoral, acetabular offset, leg length discrepancy, acetabular anteversion, acetabular position, and component size, while adjusting for surgical approach and spinal pathology. RESULTS: NAS under-restored 4.8 mm of lateral femoral offset (43.9 ± 8.7 mm) after THA when compared to the uninjured side (48.7 ± 7.1 mm, p = 0.044). NAS were at risk for under-restoring lateral femoral offset when compared to EAS (p = 0.040). There was no association between lateral acetabular offset, leg length, acetabular position, or component size and surgeon type. CONCLUSIONS: Lateral femoral offset is at risk for under-restoration after THA for femoral neck fractures, when performed by surgeons that do not regularly perform elective THA. This indicates that lateral femoral offset is an under-appreciated contributor to hip instability when performing THA for a femoral neck fracture. Lateral femoral offset deserves as much attention and awareness as acetabular component position since a secondary analysis of our data reveal that preoperative templating and intraoperative imaging did not prevent under-restoration.

Lack of alignment between orthopaedic surgeon priorities and patient expectations in total joint arthroplasty.

BACKGROUND: Healthcare systems are shifting toward "patient-centered" care often without assessing the values important to patients. Analogously, the interests of the patient may be disparate with physician interests, as pay-for-performance models become common. The purpose of the study was to determine which medical preferences are essential for patients during their surgical care. METHODS: This prospective, observational study surveyed 102 patients who had undergone a primary knee replacement and/or hip replacement surgery about hypothetical scenarios regarding their surgical experience. Data analysis included categorical variables presented as a number and percent, while continuous variables presented as mean and standard deviation. Statistical analysis for anticoagulation data included the Pearson chi-square test and one-way ANOVA test. RESULTS: A large majority, 73 patients (72%), would not pay to have a four-centimeter or smaller incision. The remaining 29 patients (28%) would prefer to have a four-centimeter or smaller incision and would pay a mean of $1,328 ± 1,629 for that day. A significant number of patients preferred not to use anticoagulation (p = 0.019); however, the value attributed to avoiding a specific method of anticoagulation was found not to be significant (p = 0.507). CONCLUSIONS: The study determined the metrics prioritized by hospitals and surgeons are not important to the majority of patients when they evaluate their own care. These disconnects in the entitlements patients expect and receive can be solved by including patients in discussions with physicians and hospital systems.

Supine Knee Positioning Does Not Interfere with Mobile-Bearing Unicompartmental Knee Arthroplasty Performance.

The Food and Drug Administration has only approved mobile-bearing unicompartmental knee arthroplasty (MB-UKA) to be performed with a hanging leg holder. The purpose of this study is to evaluate the impact of a supine knee position on MB-UKA performance.In total, 16 cadavers were randomized so that either the right or left knee was placed in the flexed or supine positions. One board-certified orthopaedic surgeon and three adult reconstruction fellows that attended the required Oxford partial knee instructional course performed four operations in each position. The primary outcome was final knee balance. Secondary outcomes included procedure duration, timing of individual surgical steps, implant sizes, range of motion, implant alignment, and fracture. A Students t-test was used to examine differences between positions with significance set at p < 0.05. Secondary analyses using two one-sided tests were conducted to explore equivalence between the two positions.There was no significant difference in mean final balance between supine (1.7 mm ± standard deviation [SD] = 1.5 mm) and flexed (1.3 ± 1.3 mm) positions (p = 0.390). There were also no significant differences between positions for procedure time (p = 0.497), tibia coronal alignment (p = 0.614), tibial slope (p = 0.194), femoral component sagittal alignment (p = 0.091), and fractures (n = 0). Exploratory equivalence analyses indicated that the positions were equivalent for final balance (p = 0.002).MB-UKA performed in the supine position is not significantly different from the flexed position in terms of ligament balance, overall procedure time, and radiographic appearance. These initial safety data warrant further clinical investigations and support the expansion of the surgical technique to include performing MB-UKAs in the supine position.

Medial Unicompartmental Knee Arthroplasty with a Mobile-Bearing Implant.

BACKGROUND: For patients with isolated medial knee arthritis, unicompartmental knee arthroplasty (UKA) is an appealing surgical option. Compared with total knee arthroplasty (TKA), UKA is less invasive, preserves more native bone stock, has lower perioperative morbidity and mortality1,2, allows for quicker recovery1,2, and has higher patient satisfaction2,3. It also allows for more dynamic proprioception and postural control, allowing for function more similar to a native knee4. Proper surgical technique and patient selection are critical to the growing success of UKA. DESCRIPTION: The general principles of UKA are to remove and replace the diseased femoral and tibial joint surfaces while restoring limb alignment. The key steps of this procedure are demonstrated in the video article: (1) patient evaluation, (2) patient positioning, (3) surgical exposure, (4) tibial guide placement and resection, (5) femoral guide placement and resection, (6) knee balancing and implant trialing, (7) preventing impingement, (8) final tibial preparation, (9) final component placement, and (10) closure and postoperative course. ALTERNATIVES: Patients should first exhaust all nonoperative treatments before considering UKA. For those patients who do not meet the appropriate indications for UKA, TKA is the most acceptable alternative treatment. In active patients <55 years old without bone-on-bone osteoarthritis, a high tibial osteotomy may be considered. When considering UKA, options include both mobile-bearing and fixed-bearing designs. RATIONALE: The potential advantages of UKA over TKA make it an attractive option for the appropriate patient. Recently, indications for UKA have expanded to include (1) isolated noninflammatory bone-on-bone arthritis in the medial compartment; (2) retained full-thickness cartilage in the lateral compartment, best visualized on valgus-stress radiographs; (3) a functionally normal medial collateral ligament; and (4) a functionally normal anterior cruciate ligament5. Mobile-bearing UKA designs consist of a dual articulation between the concave polyethylene insert and the metallic tibial and spherical femoral components, which allows for distribution of contact forces over a large surface area6. In contrast, fixed-bearing designs have a flat polyethylene insert that does not conform to the femur. Current data do not demonstrate a clear difference in clinical performance between the 2 bearings. However, a recent systematic review has shown lower polyethylene wear rates in mobile-bearing implants7. EXPECTED OUTCOMES: The survivorship of mobile-bearing UKA ranges from 85% to 98% at 10 years8-12 and from 79% to 94% at 15 years8,13,14. The most common indications for revision include aseptic loosening (36%), progression of osteoarthritis (20%), and unexplained pain (11%)7. Bearing dislocation is a unique complication for mobile-bearing UKAs, with reported rates between 0.3% to 4.2%6,10,12. IMPORTANT TIPS: Always inspect all compartments of the knee for evidence of substantial degenerative changes prior to proceeding with UKA. If there is advanced arthritis in other compartments, the decision should be made to proceed with TKA instead. Therefore, preoperatively, all patients indicated for UKA should also sign a consent form for TKA, and TKA implants should be available in case they are needed.When assessing bearing size, it is important that there is no axial loading through the heel to properly assess the flexion gap. Intraoperatively, this can be done by elevating the thigh so that the foot hangs freely. The trial spoon should fit into the joint without substantial resistance or effort.Spigots do not reference the end of the bone. Rather, they reference the end of the spigot hole that was drilled using the initial 0 spigot.Spigot number represents the total thickness of additional bone that will be removed from the first mill cut.Confirm the amount of bone that was resected by inspecting the small rim of bone that remains around the spigot hole after milling.

A Small Amount of Retraction Force Results in Inadvertent Piriformis Muscle Damage During a Piriformis-Sparing Approach to the Hip.

BACKGROUND: Piriformis-sparing approaches to the hip allow surgeons to avoid releasing the piriformis tendon during total hip arthroplasty; however, the consequences of retracting an intact piriformis tendon during such an approach remain ill-defined. The present study aimed to determine the upper limit of force that can be applied during retraction of the piriformis tendon to expose the hip, and to quantify the resultant damage to the piriformis musculotendinous complex. METHODS: A patent-pending instrumented retractor was designed to record the applied force, duration, and angle of retraction during a piriformis-sparing posterior approach to the hip. In addition to the data collected with use of the instrumented retractor, damage to the piriformis muscle and tendon was quantified by a blinded observer. RESULTS: There was no damage to the piriformis tendon in 22 (96%) of 23 hips during piriformis retraction for visualization of the hip capsule; however, there was complete or partial damage to the piriformis muscle at the sacral origin, belly, or musculotendinous junction (i.e., outside the surgical field) noted in 21 (91%) of 23 hips. The mean peak force to failure of the piriformis muscle was exceedingly small (29.0 ± 9.4 N; range, 10.1 to 44.9 N). CONCLUSIONS: The mean peak force applied to the piriformis retractor is much less than the force required for several common daily activities, such as opening a door or crushing an empty aluminum can. Soft-tissue damage that occurs outside the surgical field during the retraction of unreleased muscles, like the piriformis muscle, is common and remains an uncontrolled surgical variable. This inadvertent soft-tissue damage is not routinely accounted for when accessing the invasiveness of a procedure. Hence, it is no longer adequate to define a minimally invasive surgical procedure simply as an approach that involves the limited release of anatomical structures. CLINICAL RELEVANCE: The use of instrumented retractors may redefine surgical invasiveness by providing data that could alter our understanding of the soft-tissue damage caused by retraction and open the possibility of robot-assisted or damage-limiting retractor systems.

Learning Curve for the Direct Superior Approach to Total Hip Arthroplasty.

Surgical learning curves are a representation of the number of cases required for a surgeon to reach a stable rate of outcomes and complications. In this study, the authors present the learning curve for the direct superior (DS) approach to total hip arthroplasty, which is a muscle-sparing modification to the mini-posterior technique. This was a retrospective analysis of the first 40 primary DS cases done by a single surgeon. These cases were divided into 2 groups of 20 and compared for intra- and postoperative complications, acetabular component positioning, and Harris Hip Score at 90 days after surgery. As a control, the first 20 primary mini-posterior cases were analyzed as the baseline performance of the surgeon and the DS approach. There was no statistically significant difference between the first and second sets of DS patients regarding Harris Hip Score, intraoperative complications, dislocations, estimated blood loss, length of hospital stay, and components positioned within the Lewinnek safe zone. The only statistically significant difference between the first and second sets of DS cases was a decrease in operating time (P<.001). This suggests that the learning curve is less than 20 patients. The results also indicate that the first 20 DS cases ambulated farther (P=.007) and had a shorter length of stay (P=.007), outperforming the mini-posterior approach. This study suggests that the DS learning curve is short for surgeons trained in the posterior approach. The data could be especially pertinent as 90-day results and safety are becoming increasingly important in evaluating performance for bundled-payment models. [Orthopedics. 2020;43(4):e237-e243.].

Total Knee Arthroplasty Has A Positive Effect on Patients With Low Mental Health Scores.

BACKGROUND: The purpose of this study is to determine the impact of total knee arthroplasty (TKA) on mental health. METHODS: A total of 205 patients who underwent primary TKA with baseline and 1-year postoperative Short Form-12 Mental Component Score (MCS) were included in this retrospective analysis. Eighty-five (41%) patients had a preoperative MCS less than 50 points, while 120 (59%) patients had a preoperative MCS over 50 points. Two groups were assigned to the patients based on their preoperative MCS: low MCS <50 and high MCS >50. RESULTS: A preoperative MCS less than 50 points was predictive of greater improvement in MCS at 1 year after TKA (P < .001). Patients with low MCS improved by a mean of 10.6 points from 39.1 ± 8.6 points preoperatively to mean of 49.7 ± 10.7 points 1 year after TKA (P < .001). Patients with a high MCS decreased by a mean of 3.5 points from 60.01 ± 6.0 points preoperatively to mean of 56.6 ± 6.8 points 1 year after TKA (P < .001). This remained higher than the postoperative MCS of the patients with a low MCS, 49.7 ± 10.7 (P < .001). The patients with a high MCS had greater improvement in the Short Form-12-Physical domain (14.8 points) than the patients with a low MCS (9.2 points, P < .001). CONCLUSION: Patients with lower baseline mental health had greater improvement in postoperative mental health following TKA than patients with higher baseline mental health. Low preoperative MCS was associated with less improvement in patient-reported outcome measures. Patients with lower baseline mental health scores before TKA benefit mentally and physically from the procedure.

Direct Superior Approach to the Hip for Total Hip Arthroplasty.

BACKGROUND: Traditional posterior approaches to the hip, posterolateral and mini-posterior, violate the iliotibial band and the short external rotators, specifically the quadratus femoris and obturator externus muscles1-4. The direct anterior approach does not violate the iliotibial band or the quadratus femoris, resulting in earlier ambulation and lower dislocation rates1,5-9. The direct superior (DS) is a posterior approach that spares the iliotibial band, obturator externus tendon, and quadratus femoris muscle. The goal of minimally invasive surgery (MIS) is to disrupt the least amount of tissue necessary to adequately expose the hip and correctly place implants. Although MIS total hip arthroplasty (THA) has not lived up to all of its promises10-13, MIS-THA may enable early ambulation and decrease length of stay14-16. DESCRIPTION: The patient is positioned in the lateral decubitus position. An 8 to 10-cm incision is made at a 60° oblique angle starting from the posterior-proximal corner of the greater trochanter. Only the gluteus maximus fascia is incised; the Iliotibial band is completely spared. The gluteus maximus muscle is split bluntly, exposing the gluteus medius muscle, piriformis tendon, and triceps coxae (the obturator internus and superior and inferior gemellus muscles). The piriformis and conjoined tendon are released from the greater trochanter and tagged. The gluteus minimus is elevated, exposing the posterior hip capsule. An arthrotomy is performed prior to dislocating the hip with flexion, adduction, internal rotation, and axial compression. The femoral neck is resected, the acetabulum is reamed, and components or trials are impacted into position. Hip stability is assessed. Final implants are placed. The posterior capsule, piriformis, and obturator internus tendons are repaired anatomically. The fascia and skin are closed. ALTERNATIVES: Posterolateral approach.Mini-posterior approach.Direct lateral approach.Anterolateral approach.Percutaneously assisted total hip (PATH).Supercapsular PATH (SuperPath). RATIONALE: The DS approach to the hip differs from the traditional posterior and mini-posterior approaches because it preserves the iliotibial band, quadratus femoris muscle, and obturator externus tendon1, potentially suppressing dislocation. The DS approach to the hip causes less soft-tissue destruction, especially to the gluteus minimus and tensor fasciae latae muscles, compared with the direct anterior approach to the hip, suggesting DS-THA may enhance postoperative mobility1,3,14-16. DS-THA is extensile by extending the incision distally, incising the iliotibial band, and releasing the quadratus femoris muscle. This converts a DS approach to a standard posterolateral approach, providing additional visualization.