Surgical technique: a simple soft-tissue-only repair of the capsule and external rotators in posterior-approach THA

The short external rotator muscles of the hip: a cadaveric study on 18 specimens with clinical implications

PURPOSE

The short external rotator muscles (SERMs) of the hip are composed of six postural muscles that constitute a single functional unit that is aligned to coapt the articular surfaces of the hip joint, providing dynamic stability. This study aims to provide a morphometric evaluation of this unit that could benefice clinical practice. In particular, the implication of the morphology and direction of the hip triceps tendon when performing a posterolateral approach for total hip arthroplasty.

METHODS

A total of 18 cadaveric hips were dissected rigorously. Variations of the origin, course and insertion of all SERMs were recorded and quantified. Measurements were conducted for the following parameters: total muscle lengths, intra-muscular and extra-muscular tendon lengths, muscle sagittal and frontal angles, and femoral neck length. Correlation was searched for between total muscle length and femoral neck length.

RESULTS

Results were as follows: (a) the obturator internus and externus muscles insert quasi perpendicularly on the proximal femur, (b) both gemelli take distal insertion onto the tendon of the obturator internus to form the hip triceps tendon, (c) morphometric data of the studied parameters was reported, and (d) moderate to high correlation with femoral neck length was found for all muscles but the quadratus femoris.

CONCLUSION

Our results showed that the direction of the hip triceps tendon is always orthogonal to the proximal femur in the frontal plane. Such anatomical reference could be used when performing total hip arthroplasty with the posterolateral approach. Future research is needed to assess whether the easy identification and re-insertion of the hip triceps could reduce leg length discrepancy and offset.

Approaching total hip arthroplasty after Legg-Calvé-Perthes disease: A case series and literature review

Due to femoral head-neck deformities and hip joint incongruence, patients with Legg-Calvé-Perthes Disease (LCPD) commonly require total hip arthroplasty (THA) in the fifth and sixth decades of life. These patients present additional challenges to arthroplasty surgeons not only because of their complicated hip anatomy but also because patients may have undergone prior operative procedures in childhood and thus present with pre-existing proximal femoral deformities. THA in LCPD patients can be associated with peri-operative complications such as fracture or nerve injury, and the rate of reoperation has been reported to be higher in the LCPD population as compared to the general population undergoing THA. Despite this, multiple case reports and studies have shown the relative long-term success of THA in patients with history of LCPD. In particular, uncemented modular stems are a commonly used implant choice in such cases. This article reviews and discusses the technical considerations for THA in patients with LCPD and highlights three such cases.

Selective THA-approach use amongst junior surgeons improves safety of introducing the anterior approach: a prospective, multi-surgeon, comparative, study

BACKGROUND

Learning curves associated with independent practice and anterior approach total hip arthroplasty (AA-THA) has been associated with inferior outcome. This study compared outcome of junior, fellowship-trained, surgeons who perform THA through both anterior and posterior (PA) approach, with senior surgeons who perform either AA or PA, to determine whether: 1. Fellowship training and selective practice allows for safe introduction of AA into practice; and 2. Whether selective approach-use influences outcome.

METHODS

This is a prospective, consecutive study comparing the first 800 THAs of two junior, dual-approach, surgeons (AA/PA: 455/345), with 400 THAs cases of two senior, single-approach, surgeons (AA/PA: 200/200), between 2018 and 2020. Most patients were female (54.4%), mean age was 65 years-old (range 19-96) and mean BMI was 29 kg/m2 (range 16-66). Outcome included radiologic measurements (inclination/anteversion and leg-length), complication- and revision rates, and patient-reported outcomes including Oxford Hip Score (OHS).

RESULTS

At 3.1 years (range 2.0-6.8) follow-up, there were 43 complications (3.6%), including 27 re-operations (2.3%); with no difference between junior and senior surgeons for AA-THA (Junior: 8/455 vs. Senior: 3/200; p = 0.355) or PA-THA (Junior: 11/345 vs. Senior: 5/200; p = 0.400). Amongst juniors, there was no difference in complications (AA:8/455 vs. PA:11/345; p = 0.140) and in ΔOHS (AA:20.5 ± 7.7 vs. PA:20.5 ± 8.0; p = 0.581) between approaches.

CONCLUSION

Contemporary training and selective approach-use minimizes the learning curve, allowing junior staff to have equivalent outcome to established, senior surgeons in both AA and PA. We would advocate for selective approach use amongst junior arthroplasty surgeons when introducing the AA into independent practice.

Use of electrocautery devices for suture passage through the greater tuberosity: a biomechanical study

BACKGROUND

The use of electrocautery to facilitate passage of a suture needle through bone without the aid of a drill or burr is a novel technique that has potential utility in orthopedic procedures, but there is a scarcity of research to support its utility. The specific aims of this cadaveric biomechanical study were to evaluate (1) the axial force reduction during suture passage using electrocautery when applied to rotator cuff repair, (2) the temperature change caused while using electrocautery, and (3) the failure loads and failure modes of this technique.

METHODS

Five matched pairs of fresh frozen humeri were used, classified into 2 groups: with electrocautery on needle (study group) and without electrocautery on needle (control group). Four individual osseous tunnels were made on the greater tuberosity around the insertion of the supraspinatus tendon. Each specimen was sequentially tested in 2 parts: a needle penetration test (part I) to measure the peak axial force and temperature change and a single load-to-failure test (part II) to measure the maximum load to failure as well as the mechanism of failure. A No. 2 FiberWire suture with a straight needle was used.

RESULTS

In part I, the mean peak axial force was lower in the study group compared with the control group for all osseous tunnels but was not statistically significant for individual tunnels. However, there was a significant decrease in peak axial force in the study group of 36% compared with the control group overall (P = .033). There was no significant change in temperature of the tunnel site with the use of electrocautery (mean: 0.2 ± 0.3°C, P = .435). In part II, 100% of the samples from each study group experienced bone tunnel failure. Forty percent of the trials in the study group found lower ultimate failure loads compared with the control group (reduction range: 7%-38%). There was no statistically significant difference in the ultimate failure load between either the loop tested or between the 2 study groups (loop 1: P = .352; loop 2: P = .270).

CONCLUSION

Suture passage using electrocautery does significantly decrease the peak force needed to pass a needle directly through the greater tuberosity. This technique does not appear to burn the bone or weaken the bone tunnels. This technique may be useful during open rotator cuff repair or shoulder arthroplasty, although clinicians should be cautious when using this technique as its utility depends on bone quality and cortical thickness, and in vivo results may differ.

Total Hip Arthroplasty: Direct Anterior Approach Versus Posterior Approach in the First Year of Practice

Background

The direct anterior approach (DAA) for total hip arthroplasty (THA) has been popularized as a less invasive technique, however outcomes within the first year of practice after fellowship have not been investigated. The primary aim was to determine differences in complications and outcomes between DAA and posterior approach (PA) in the first year of practice. The secondary aim was to determine if there was a learning curve factor in DAA and PA after fellowship training.

Methods

THA cases performed by two surgeons during their first year of practice were reviewed. Overall, 181 THAs (91 DAA, 90 PA) in 168 patients, were performed. Intraoperative differences (blood loss, operative time), hospital stay, complications, reoperations, and revisions were compared.

Results

Overall surgical complications were similar between DAA and PA (11% vs. 9%, p=0.64), but complication profiles were different: dislocation (1% vs. 4%, p=0.17), intraoperative femoral fracture (2% vs. 1%, p=0.32), postoperative periprosthetic fractures (2% vs. 3%, p=0.64). neuropraxia (3% vs. 0%, p=0.08). There was no difference in rate of reoperation (1% vs. 3%, p=0.31). There was a difference in rate of revision at final follow-up (0% vs. 6%, p=0.02). DAA consisted of longer operative time (111 vs. 99 minutes; p<0.001), however was only significant in the first 50 cases (p<0.001), while the subsequent cases were similar (p=0.31). There was no difference in the first 50 cases compared to the subsequent cases for either approach regarding blood loss, complications, reoperations, or revisions.

Conclusion

DAA and PA for THA performed within the first year of practice exhibit similarly low complication rates, but complication profiles are different. In our series, PA did demonstrate a higher risk of revision at final follow-up. A learning curve is not unique to the DAA. Both DAA and PA THA exhibited a learning curve in the first 50 cases performed at the start of a surgeon's practice. Level of Evidence: III.

Randomized Clinical Study on the Efficacy of Direct Anterior Approach Combined With Tendon Release and Repair After Total Hip Arthroplasty

Background

To study the effect of reconstruction of the joint capsule and conjoint tendon on the functional recovery of the hip joint during direct anterior approach (DAA) total hip arthroplasty.

Methods

A total of 60 patients who underwent their first total hip arthroplasty surgery were selected. According to the set criteria, the selected patients were divided into observation group A (n = 30) and control group B (n = 30). In group A, the joint capsule and conjoint tendon (superior muscle, internal obturator muscle, and inferior muscle) were repaired in situ, while in group B, only the joint capsule was repaired in situ, and the conjoint tendon was not repaired. The surgical indicators, including hip joint function and clinical efficacy of the two groups, were compared.

Results

After 6 months of follow-up in groups A and B, no dislocation occurred. The Harris Hip scores of group A were higher than those of group B at 1-month post-operation, i.e., p < 0.05, as well as the valid muscle strength and conjoint tendon valid tension, were higher in group A than group B at 1-month postoperative follow-up, i.e., p < 0.05.

Conclusion

DAA for total hip arthroplasty on the premise of reconstructing the joint capsule structure can rebuild the tension of the conjoint tendon, enhance its muscle strength, and significantly improve the joint stability and function of the patient early stage. It is beneficial for the patient's rapid recovery and is worth implementing.

Two year follow up of supercapsular percutaneously assisted total hip arthroplasty

BACKGROUND

Dislocation after primary total hip arthroplasty (THA) has an incidence of 2-3%. Approximately 77% of dislocations occur within the first year after surgery. The SuperPATH technique is a minimally invasive approach for THA that preserves soft tissue attachments. The purpose of this study is to describe the dislocation rate at 1 year after SuperPATH primary THA.

METHODS

All elective primary THAs performed by the senior author using the SuperPATH approach. Exclusion criteria were acute femoral neck fracture, revision surgery, or malignancy. There were 214 of 279 eligible patients available for telephone interviews (76.7%). Medical records were reviewed for secondary outcomes including early and late complications, cup positioning, distance ambulated on postoperative day one, discharge destination, and blood transfusions.

RESULTS

Mean age at surgery was 64 ± 10.8 years and mean time to telephone follow up was 773 ± 269.7 days. There were 104 female and 110 male patients. There were zero dislocations reported. Blood transfusions were performed in 3.7% of patients, and 75.7% were discharged to home at an average of 2.3 ± 1.0 days. Cup position averaged 43.6 ± 5.2° abduction and 20.9 ± 6.2° anteversion, with an average leg length discrepancy of 3.6 ± 3.32 mm. Complications included three intraoperative calcar fractures, one periprosthetic femur fracture, one early femoral revision, three superficial infections, and one instance of wound necrosis.

CONCLUSION

SuperPATH approach is safe for use in primary THA resulting in a low dislocation rate.

Functional and clinical anatomy of the obturator externus muscle: Cadaveric studies and clinical findings for total hip arthroplasty in the posterior approach

Repairing released posterior soft tissues is important in preventing dislocation after total hip arthroplasty (THA) via the posterior approach. We clarify the functional and the clinical anatomy of obturator externus. We performed cadaveric studies and investigated clinically in primary THA cases. The location, trajectory, and size of the muscular tendon was recorded. The trajectory of the obturator externus ran orthogonal to the femoral axis with the hip in 90° flexion whereas that of the obturator internus muscle ran parallel. Because the trajectory of obturator externus and the obturator internus differ, their functions also differ.

Soft-Tissue Balancing in Total Hip Arthroplasty

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Appropriate total hip arthroplasty (THA) reconstruction must simultaneously address component position, restoration of biomechanics, and soft-tissue balance.

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Preoperative planning for complex THA cases should include radiographic templating, a detailed case plan that contains backup implant options, and a thorough understanding of the patient's preoperative examination.

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Using a systematic approach to soft-tissue balancing in THA enhances the ability to intraoperatively execute the preoperative plan.

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In patients with preexisting deformities (e.g., dysplasia or prior surgery), increased attention to abductor function is necessary when assessing acetabular component placement and offset.

A Specific Capsular Repair Technique Lowered Early Dislocations in Primary Total Hip Arthroplasty Through a Posterior Approach

BACKGROUND

Dislocation is a challenging problem after total hip arthroplasty (THA). We sought to evaluate the incidence of early dislocation with 2 different posterior repair techniques after THA using a posterior approach.

METHODS

From September of 2008 to August of 2019, we evaluated 841 THAs performed by a single surgeon using a posterior approach. Before November of 2015, the capsule was repaired to the greater trochanter (group 1, 605 patients). Starting November 2015, the posterior capsule was repaired in a side-to-side fashion (direct soft-tissue repair) (group 2, 236 patients). There was a mean follow-up of 31.1 months (range, 2.5-122.5 months). A multivariable logistic regression model was constructed to assess the impact of baseline patient and operative factors on the dislocation rate.

RESULTS

There were 22 dislocations, all of which occurred in group 1. There were no dislocations in group 2. After adjusting for patient and operative factors, the direct soft-tissue repair had a large impact on the overall multivariable model as indicated by its effect likelihood ratio of 10.33 (P = .001); however, the odds ratio was not calculable for this factor, given that there were no dislocations in hips with direct soft-tissue repair. Increasing age was associated with an increased odds of dislocation (odds ratio, 1.04, P = .017), with an effect likelihood ratio of 6.25 (P = .012).

CONCLUSIONS

Switching from a capsular repair to the greater trochanter to a side-to-side capsular repair was associated with a decreased rate of dislocation in primary THA through a posterior approach.

Introduction of a New Treatment Algorithm Reduces the Number of Periprosthetic Femoral Fractures After Primary Total Hip Arthroplasty in Elderly Females

BACKGROUND

Increasing global usage of cementless prostheses in total hip arthroplasty (THA) presents a challenge, especially for elderly patients. To reduce the risk of early periprosthetic femoral fractures (PFFs), a new treatment algorithm for females older than 60 years undergoing primary THA was introduced. The aim of this study was to determine the impact of the new treatment algorithm on the early risk of perioperative and postoperative PFFs and guideline compliance.

METHODS

A total of 2405 consecutive THAs that underwent primary unilateral THA at our institution were retrospectively identified in the period January 1, 2013-December 31, 2018. A new treatment algorithm was introduced on April 1, 2017 with female patients aged older than 60 years intended to receive cemented femoral components. Before this, all patients were scheduled to receive cementless femoral components. Demographic data, number of perioperative and postoperative PFFs, and surgical compliance were recorded, analyzed, and intergroup differences compared.

RESULTS

The utilization of cemented components in female patients older than 60 years increased from 12.3% (n = 102) to 82.5% (n = 264). In females older than 60 years, a significant reduction in the risk in early postoperative and intraoperative PFF after introduction of the new treatment algorithm was seen (4.57% vs 1.25%; P = .007 and 2.29% vs 0.31%; P = .02, respectively). Overall risk for postoperative and intraoperative fractures combined was also reduced in the entire cohort (4.1% vs 2.0%; P = .01).

CONCLUSION

Use of cemented fixation of the femoral component in female patients older than 60 years significantly reduces the number of PFFs. Our findings support use of cemented femoral fixation in elderly female patients.

Anatomic Total Hip Component Position Is More Reproducible With the Direct Anterior Approach Using Intraoperative Fluoroscopy

Background

Total hip arthroplasty (THA) has demonstrated excellent results regardless of the surgical approach. However, the approach used may be a factor in final positioning of implants. We hypothesized that the direct anterior approach (DAA) with fluoroscopy would be associated with more anatomic implant positioning than the posterior approach (PA).

Methods

A retrospective review of 200 patients was performed. One hundred patients underwent THA utilizing the PA, and 100 patients, with the DAA. All patients had an anterior-posterior pelvis radiograph preoperatively and postoperatively with a magnification marker present to standardize each radiograph. Exclusion criteria included contralateral THA or any pelvic or femoral deformity.

Results

Preoperative radiographs demonstrated identical cohorts with respect to leg length, femoral offset, and total offset. Postoperatively, the DAA achieved more accurate anatomic restoration of leg length (1.6 mm vs 5.5 mm; P < .0001), femoral offset (4.8 mm vs 9.3 mm; P < .0001), and total offset (0.5 mm vs 4.7 mm; P < .0001) compared with the PA. Ideal cup abduction and anteversion were significantly superior to the DAA (96% vs 78%, P = .0002, and 69% vs 24%, P < .0001, respectively).

Conclusions

This study is the first to compare anatomic implant positioning between patients undergoing THA with these 2 approaches. All parameters were significantly closer to anatomic implant positioning with the DAA. There are at least 2 potential explanations for this: (1) The DAA implant positioning was performed under fluoroscopic guidance, whereas the PA was not. (2) The PA disrupts the posterior capsule and external rotators, and therefore, increased offset or leg length may be necessary to achieve comparable hip stability with the DAA.

Transitioning the total hip arthroplasty technique from posterior approach in lateral position to direct anterior approach in supine position-risk factors for acetabular malpositioning and the learning curve

PURPOSE

Cup positioning is important for optimum hip stability, avoiding component impingement and decreasing both bearing surface wear and revision rate. Transitioning from posterior approach in a lateral position to direct anterior approach (DAA) in a supine presents unique challenges for surgeons. The aim of this study was to examine the learning curve when using standard instrumentation that was not specific to DAA.

METHODS

A consecutive retrospective series of 537 total hip arthroplasty by DAA from May 2013 to December 2017. Cup positioning was analysed on radiographs and classified whether inside or outside two safe zones (inclination 30-50° and anteversion 10-30°). The demographic data (age, BMI, gender, neck shaft angle (NSA)), surgeon's dominant side and experience were assessed as risk factors.

RESULTS

Eighty per cent of cups (n = 426) were in the combined safe zones. Eighty-eight per cent (n = 470) were in appropriate anteversion and 87% (n = 463) abduction. Two factors that were significant were identified: Cups of left hips operated by right-handed surgeons were more anteverted (OR = 4.06) and more vertical (OR = 2.23); females had a higher anteversion of the cup (OR = 2.42). Obesity, age and NSA were not risk factors for cup malposition. There was a spike of cups too horizontal at the beginning of the experience (OR = 3.86), and no learning curve was observed in the other orientations.

CONCLUSION

With our DAA technique using standard instrumentation, there were no risk factors linked to the patient identified for cup malposition. DAA-specific instrumentation is not required to achieve optimum positioning of the cup. Surgeon has to be aware of an excess of abduction at the beginning of his experience and an excess of anteversion and adduction when performing THA on the opposite side of his dominant hand.

Fascia and soft tissues innervation in the human hip and their possible role in post-surgical pain

Persistent symptoms, most commonly pain, may remain after otherwise successful hip replacement surgery. Innervation of fascia and soft tissues has become increasingly important in etiopathogenesis of pain, but the relative importance of the various anatomical structures in the hip region is still not known. Innervation of skin, superficial adipose tissue, superficial fascia, deep adipose tissue, deep fascia, muscles, capsule, capsule ligament, ligamentum teres, and tendon in the human hip from 11 patients and 2 cadavers were quantified by staining with anti-S100 antibody for myelin-forming Schwann cells, to obtain the percentage of antibody positivity, density and mean diameter of the nerve fibers. The skin was the most highly innervated (0.73% ± 0.37% of positive area in patients; 0.80% ± 0.28% in cadavers); the tendon was the least innervated (0.07% ± 0.01% in patients, 0.07% ± 0.007% in cadavers). The muscles (vasto-lateral and gluteus medius) were the second most innervated structure according the percentage (0.31% ± 0.13% in living humans, 0.30% ± 0.07% in cadavers), but with only a few nerves, with large diameters (mean diameter 36.4 ± 13.4 µm). Instead, the superficial fasciae showed 0.22% ± 0.06% and 0.26% ± 0.05% of positive areas in living humans and cadavers, respectively. Fasciae were invaded by networks of small nerve fibers, revealing a possible role in pain. The superficial fascia was the second most highly innervated tissue after the skin, with a density of 33.0 ± 2.5/cm² , and a mean nerve sizes of 19.1 ± 7.2  µm. Lastly, the capsule turned out to be poorly innervated (0.09%), showing that its removal does not necessarily lead to painful consequences. Statement of clinical significance: Deeper knowledge about the innervation of the soft tissue in the human hip joint will enhance study and understanding of the best surgical procedures to follow during hip arthroplasty to reduce post-operative pain.

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.].

Length of Stay, Discharge Disposition, and 90-Day Complications and Revisions Following Primary Total Hip Arthroplasty: A Comparison of the Direct Anterior, Posterolateral, and Direct Superior Approaches

BACKGROUND

The direct anterior (DA) approach is becoming increasingly popular for primary total hip arthroplasty (THA). The aim of this study is to evaluate early postoperative complication and revision rates based on surgical approach, comparing DA, posterolateral (PL), and direct superior (DS) approaches.

METHODS

After institutional review board approval, a total joint arthroplasty database from a single institution was used to identify all patients who underwent elective primary THA between July 2013 and November 2017 with a DA, PL, or DS hip approach. Patients were followed for complications out to 90 days postsurgery. Patients were divided into groups based on surgical approach and compared on length of stay, discharge disposition, and 90-day complication and revision rates.

RESULTS

There were 5341 THA procedures performed, with 3162 PL, 1846 DA, and 333 DS approaches. Length of stay was shorter for DS (1.7 ± 0.9 days) and DA (1.8 ± 0.9 days) than for PL approaches (2.3 ± 1.4 days, P < .001) The DS approach had the highest rate of home discharges (93.1%), but the highest short-term revision rate (1.5%, P = .011). The DA approach had the lowest intraoperative fracture rate (0.1%, P = .019) but the highest incidence of postoperative fractures (1.3%, P = .021). There were no differences in readmission (P = .056), 90-day events (P = .062), emergency department visits (P = .210), dislocations (P = .090), combined perioperative fractures (P = .289), venous thromboembolic events (P = .059), or acute infection rates (P = .287).

CONCLUSION

In the era of bundled payments, the DA, PL, and DS approaches can all be effectively used.

LEVEL OF EVIDENCE

Level III; retrospective comparative study.

The utility of electrocautery for suture passage through bone: A biomechanical study

Electrosurgical devices are routinely employed during surgery. The use of a Bovie Electrosurgical Unit (ESU) to facilitate the passage of a suture needle through bone has not been studied in the literature. This study aimed to identify force reduction with the application of Bovie ESU to the suture needle through the bone. Peak and the average axial force required for a suture needle to penetrate cadaveric proximal humeri were measured using a custom setup. Twenty-four trials were conducted without electricity, and 72 trials were conducted with a Bovie ESU applying current. Needle size and Bovie ESU power settings were varied. t Tests and analysis of variance were used with p ≤ 0.05 denoting statistical significance. The application of electricity reduced the peak and average axial force needed for a needle to pierce bone, regardless of the Bovie ESU power setting (p < 0.001). The average peak force with the Bovie ESU was 65.7 N, compared with 126.0 N without (p < 0.001), a 47.9% reduction. The average axial force with the Bovie ESU was 38.2 N compared with 81.8 N without (p < 0.001), a 53.3% reduction. There was no significant difference in peak or average axial forces between power settings. At 30 and 90 W of power, larger needle size was associated with significantly lower peak (p = 0.001 and p < 0.001, respectively) and axial (p = 0.002 and p = 0.004, respectively) force. The Bovie ESU reduces the axial force required to pass a suture needle through bone. The use of this technique may allow for the avoidance of drilling for soft tissue repair. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:954-960, 2020.

Modified osteotomy of posterolateral overhanging part of the trochanter via posterior approach for hip arthroplasty: an anatomical study

Backgroud

The osteotomy of the posterolateral overhanging part (PLOP) of the greater trochanter via posterior approach has been used for the hip arthroplasty for decades with good results. However, the osteotomy method remains undefined and the precise adjacent structures around PLOP have not been reported. The purpose of this study was to present a modified PLOP osteotomy approach and perform a detailed study of the topographic and surgical anatomy of the PLOP.

Methods

The peri-PLOP soft tissue and the bony parameters were measured using 10 cadavers with 20 hips and 20 skeletal hip specimens, respectively.

Results

A 1.8-cm vertical osteotomy did not jeopardize the femoral neck, and a 1.8-cm wide bone block did not damage the insertions of the short external rotators. The average distances between the most distal branch of the superior gluteal nerve/artery and the 1.8-cm point of the greater trochanter were 5.70 ± 0.66 cm and 6.33 ± 0.56 cm, respectively.

Conclusion

For osteotomy of the PLOP, we suggested that the width of the upper side from the lateral to medial greater trochanter should be 1.8 cm, depth of vertical osteotomy should be 1.8 cm, and length of the posterior edge should be 4 cm. Obturator externus tendon should be kept within the bone block of osteotomy. The proximal extension of the gluteus medius muscle split should be limited to 5.5 cm at the 1.8 cm-point of the greater trochanter.

Level of evidence

Prospective comparative study Level II.

Biomechanical Substantiation of the Strength and Stiffness of a Hip Joint Capsule Defect Fixation with Polypropylene Mesh

Formulation of the problem  Dislocation of the femoral component of the endoprosthesis is one of the most frequent complications of total hip replacement. The best option for the “treatment” of dislocation of the hip endoprosthesis is to prevent the development of primary instability. There are cases in which even with the correct installation of the endoprosthesis components, dislocations arise due to the weakness or defect of the capsular–ligament apparatus. Currently, many methods have been developed to strengthen and restore the posterior structures of the capsule of the hip joint with the help of auto- and allomaterials, which differ in both the fixation technique and the characteristics of the materials themselves. In this paper, we propose a method for restoring and strengthening the posterior structures of the capsule of the hip joint using polypropylene-based graft implants. The purpose of this study is to, with the help of specialized software, build a model of the capsule of the hip joint after capsulotomy and to determine the stiffness capabilities of the defect covered with polypropylene mesh.

Results  The study was performed using a software package based on the finite-element method. As a result of the performed calculations, pictures of the distribution of the stress–strain state in the “head-capsule” system were obtained. To assess the effectiveness of the method of closing the capsule, from the viewpoint of rigidity, as the main characteristics, the values of the opening of the cut are selected.

Conclusions  Under the kinematic loading of the model, the smallest values of the opening of the section are obtained when it is closed by a grid. In the case of thread fixation, the values were higher by 8.5%. However, the values of equivalent stresses, both in the capsule and in the head, in the model with the grid turned out to be the largest. These stresses were higher by 23.8% in the capsule and by 60.4% in the head than the same values for the thread fixation model. The obtained results indicate that the model with a grid is more rigid in the considered fixation variants.

The effect of conjoint tendon release on gait after direct anterior total hip arthroplasty

INTRODUCTION

There has been considerable interest in the direct anterior (DA) approach to total hip arthroplasty (THA) recently. To facilitate exposure of the proximal femur it is sometimes necessary to release the conjoint tendon.

AIM

To prospectively investigate whether release of the conjoint tendon has an impact on gait in the early postoperative period.

METHODS

We measured gait velocity, stride length, single-limb support and single-limb support symmetry preoperatively, at discharge from the hospital, and 2, 6 and 12 weeks and postoperatively. Participants also completed the Timed Up and Go and a series of questionnaires (WOMAC, SF-12, Harris Hip Score, and pain VAS) at each visit.

RESULTS

36 participants undergoing a DA THA with a single surgeon were enrolled in this study. 22 participants had a release of the conjoint tendon during their surgery. We found no differences between the groups for any gait, patient-reported or surgical outcomes (p < 0.05). There was a total of 3 complications reported in the release group, and 1 complication in the group that did not have a release.

CONCLUSION

Although the conjoint tendon has an important role in the biomechanics of the hip, we found release of the conjoint tendon during the DA approach for THA to have no impact on gait or patient reported outcomes within 12 weeks post-surgery. Therefore, if the exposure of the proximal femur is limited, a low threshold for release of the conjoint tendon is recommended to improve visualisation.

Comparison of Two Posterior Soft Tissue Repair Techniques to Prevent Dislocation after Total Hip Arthroplasty via the Posterolateral Approach

BACKGROUND

Although the posterolateral approach is considered to carry a higher early dislocation rate after total hip arthroplasty, posterior soft tissue repair techniques make up for this limitation. Through-bone and through-tendon repair techniques are the two most commonly used techniques. This study aimed to comprehensively compare these techniques and give more evidence-based references for orthopedists. Methods: This retrospective study enrolled 87 patients who underwent posterior soft tissue repair with total hip arthroplasty via the posterolateral approach. The posterior capsular and external rotators were reconstructed to the greater trochanter through drill holes (through-bone, n = 46) or gluteus medius tendon (through-tendon, n = 41). Early dislocation rate, repair-related complications, postoperative pain (visual analog scale, VAS), hip joint function (Harris Hip Scale, HHS), patient satisfaction, and operation-related indexes were evaluated. Results: The discrepancy in early dislocation between the two cohorts was not statistically significant. Operation-related indexes were not significantly different between the two cohorts, except for the postoperative drainage volume (229.46 mL vs. 172.07 mL, p=.013). No patient sustained greater trochanteric fracture and sciatic nerve injury. Each group achieved significant improvements in HHS and VAS scores compared with preoperative values. No statistically significant discrepancy was found in HHS scores between the two groups at the same period, while VAS scores were significantly lower in the through-bone group at 1 week (4.93 vs. 5.68, p=.026) and 1 month (1.72 vs. 1.99, p=.038) after surgery. Higher patient satisfaction was observed in the through-bone group. Conclusions: Although no statistical discrepancy in the early dislocation rate between through-bone and through-tendon repair techniques was observed, lower pain scores and higher patient satisfaction supported the former. We recommend that through-bone repair technique should be chosen first by orthopedists when performing reconstruction of the posterior soft tissue in total hip arthroplasty via a posterolateral approach.

Effect of articular capsule repair on postoperative dislocation after primary total hip replacement by the anterolateral approach

Objective

Artificial hip dislocation is one of the most serious complications following total hip replacement. This study was performed to assess articular capsule repair in primary total hip replacement with the anterolateral approach (Watson-Jones incision) and its effect on postoperative dislocation.

Methods

Patients who underwent primary total hip replacement by the anterolateral approach in Tongren Hospital of Shanghai Jiao Tong University School of Medicine from June 2007 to June 2014 were retrospectively analyzed. The patients were divided into the repair and dissection groups based on the articular capsule repair status during surgery. Postoperative dislocation rates were compared between the two groups using the chi-squared test.

Results

The repair and dissection groups comprised 137 and 248 patients, respectively. All patients were followed up for 6 months to 5 years (average, 3.75 years). The mean age, sex, disease composition, and follow-up time were not significantly different between the two groups. Early postoperative dislocation occurred in 1 hip (0.7%) in the repair group and 13 hips (5.2%) in the dissection group.

Conclusions

During the anterolateral approach for primary total hip replacement, articular capsule repair may reduce the occurrence of early postoperative dislocation of the hip joint.

Posterior Hip Precautions Do Not Impact Early Recovery in Total Hip Arthroplasty: A Multicenter, Randomized, Controlled Study

BACKGROUND

Posterior hip precautions have been routinely prescribed to decrease dislocation rates. The purpose of this study was to determine whether the absence of hip precautions improved early recovery after total hip arthroplasty via the posterolateral approach.

METHODS

Patients undergoing total hip arthroplasty via the posterolateral approach at 3 centers were enrolled. Patients meeting the selection criteria were randomized to standard hip precautions (SHP) or no hip precautions (NHP) for 6 weeks following surgery. HOOS Jr, Health State visual analog score, and rate of pain scores were recorded preoperatively and in subsequent postoperative visits; dislocation episodes were also noted. Standard statistical analysis was performed.

RESULTS

From 2016 to 2017, 159 patients were randomized to SHP and 154 patients were randomized to NHP. Controlling for the center at which the surgery was performed, the only difference in outcome scores between the 2 groups was at 2 weeks; the NHP group had a lower HOOS Jr score when compared to the SHP group (P = .03). There was no difference in outcome scores at any other time points when compared to preoperative assessments. In the SHP group, there were 2 recorded dislocations (1.3%) and 1 in the NHP group (0.7%; P = .62).

CONCLUSION

In this multicenter, randomized, controlled study, the absence of hip precautions in the postoperative period did not improve subjective outcomes which may be explained by the self-limiting behavior of NHP patients. Furthermore, with the numbers available for the study, there was no difference in the rate of dislocation between the 2 groups.

Surgical injury and repair of hip external rotators in THA via posterior approach: a three-dimensional MRI-evident quantitative prospective study

BACKGROUND

As one of the classical total hip arthroplasty (THA) approaches, the posterior approach is widely used. However, there is a lack of in-depth quantitative researches on the surgical-related injury to the hip external rotators. The purpose of this study is to quantificationally analyse the surgical injury of hip external rotators after posterior THA and explore the effect of the muscle repair on the muscle recovery using the MRI three-dimensional reconstruction technique combined with the clinical assessment.

METHODS

Sixty five patients were eligible to receive a unilateral cementless THA via the posterior approach. During operation, the piriformis tendon was reattached but it was not applicable for the internal obturator muscle. We performed three-dimensional MRI reconstruction of bilateral piriformis and internal obturator muscle along with clinical assessment preoperatively, 6, 12 and 52 weeks postoperatively.

RESULTS

Bilateral piriformis and internal obturator muscle were homogeneous preoperatively. Compared with the contralateral side, the volume atrophy and fat-muscle ratio of the piriformis on the operated side increased inconspicuously by 1.64%, 0.26% (p = 0.062, p = 0.071) at 6 weeks and 1.33%, 0.20% (p = 0.057, p = 0.058) at 12 weeks, while 7.28%, 2.09% and 15.71%, 5.14% for the internal obturator muscle (p < 0.01). Up to 52 weeks, the pirformis also showed significant muscle atrophy as well as fatty infiltration (increased by 7.79%, 4.21%; p < 0.01), and 24.18%, 11.91% for the internal obturator muscle (p < 0.01).

CONCLUSION

The THA via posterior approach significantly harms the hip external rotators and the early hip external rotation function. The effective repair could be conducive to the early postoperative recovery of the hip external rotators.

TRAIL REGISTRATION

The study has been registered in Chinese Clinical Trial Registry (ChiCTR) before the clical trial started, the Clinical Trial Registry Number is ChiCTR-IOR-17013007 . Registered 17 October 2017. The Trial registration is prospective registration.

Tension-free closure with capsular lengthening in mini posterior total hip replacement

PURPOSE:

Choice of the best mini invasive surgical approach for total hip replacement remains a controversial topic. The posterior approach is traditionally associated with a higher dislocation rate and the obligation of postoperative restrictions. Soft tissue repair reduces the risk of dislocation yet, posterior closure it is often challenging because of capsular and external rotator contractures. In this article, an original procedure of capsular lengthening and tension-free closure is described and the results of a retrospective single surgeon series of minimally invasive posterior total hip replacement (THR) with capsular repair are presented.

METHODS:

A total of 925 mini posterior total hip replacements performed between 2009 and 2015 were retrospectively reviewed. 2 original types of capsulorrhaphy to decrease tension of the repaired tissues were employed. Absence of posterior envelope stretch during flexion and internal rotation was confirmed intraoperatively with a dynamic test. No postoperative restrictions were used.

RESULTS:

Capsular lengthening with 1 of the described techniques was required in over 50% of cases for a tension-free closure. 3 patients dislocated in the 867 reviewed procedures (0.35%), 1 requiring revision for instability (0.11%).

CONCLUSIONS:

This soft tissue repair technique after mini posterior approach THR is technically easy, provides a tension-free closure and a low dislocation rate.

Capsular Ligament Function After Total Hip Arthroplasty

BACKGROUND

The hip joint capsule passively restrains extreme range of motion, protecting the native hip against impingement, dislocation, and edge-loading. We hypothesized that following total hip arthroplasty (THA), the reduced femoral head size impairs this protective biomechanical function.

METHODS

In cadavers, THA was performed through the acetabular medial wall, preserving the entire capsule, and avoiding the targeting of a particular surgical approach. Eight hips were examined. Capsular function was measured by rotating the hip in 5 positions. Three head sizes (28, 32, and 36 mm) with 3 neck lengths (anatomical 0, +5, and +10 mm) were compared.

RESULTS

Internal and external rotation range of motion increased following THA, indicating late engagement of the capsule and reduced biomechanical function (p < 0.05). Internal rotation was affected more than external. Increasing neck length reduced this hypermobility, while too much lengthening caused nonphysiological restriction of external rotation. Larger head sizes only slightly reduced hypermobility.

CONCLUSIONS

Following THA, the capsular ligaments were unable to wrap around the reduced-diameter femoral head to restrain extreme range of motion. The posterior capsule was the most affected, indicating that native posterior capsule preservation is not advantageous, at least in the short term. Insufficient neck length could cause capsular dysfunction even if native ligament anatomy is preserved, while increased neck length could overtighten the anterior capsule.

CLINICAL RELEVANCE

Increased understanding of soft-tissue balancing following THA could help to prevent instability and improve early function. This study illustrates how head size and neck length influence the biomechanical function of the hip capsule in the early postoperative period.

Soft tissue reinforcement with a Leeds-Keio artificial ligament in revision surgery for dislocated total hip arthroplasty

INTRODUCTION

Since dislocation after total hip arthroplasty (THA) greatly diminishes patient's quality of life, the THA frequently needs revision. However, it is common for the dislocation not to heal even after reconstruction, but rather to become intractable.

METHODS

The 17 patients with dislocated THA, mean age of 71 years (range 51-87 years), who underwent a revision THA together with soft tissue reinforcement with a Leeds-Keio (LK) ligament were enrolled. The purposes of reinforcement with LK ligament were to restrict the internal rotation of the hip joint, and to encourage the formation of fibrous tissue in the posterior acetabular wall to stabilise the femoral head. We determined the success rate of surgical treatment for dislocation, the Harris Hip Score (HHS), a factor of recurrent dislocation.

RESULTS

There was no recurrent dislocation in 82% of the cases (14 joints) during the mean postoperative follow-up period of 63.5 months (15-96 months). The HHS was 82 ± 18 points preoperatively and 82 ± 14 points postoperatively. Recurrent dislocation after this surgical procedure occurred in 2 hips with breakage of the LK ligaments, and intracapsular dislocation in 1 hip with loosening of the LK ligament.

CONCLUSIONS

Although the risk of recurrent dislocation still exists with this procedure, when performed to provide reinforcement with an LK ligament for dislocated THA it may be useful in intractable cases with soft tissue defects around the hip joint.

The incidence of hip dislocation and suture failure according to two different types of posterior soft tissue repair techniques in total hip arthroplasty: a prospective randomized controlled trial

PURPOSE

Although the posterolateral approach for hip arthroplasty is popular and has numerous advantages, it has been known to have a propensity for dislocation. The repair of short external rotator muscles with capsule is important for reducing dislocation. The purpose of this study is to investigate the incidence of suture failure, dislocation, and time to failure for two repair techniques for posterior soft tissue repair during total hip arthroplasty.

METHODS

In this study of 167 total hip arthroplasties in 159 patients, we reattached the short external rotator tendon with posterior capsule to the greater trochanter transosseously (tendon-to-bone, 87 hips) or the gluteus medius tendon (tendon-to-tendon, 80 hips). Radiopaque markers were attached to each suture side < 1.2 cm apart. The distance between the markers was radiographically measured at variable time points postoperatively. Failure was defined by a distance between markers of ≥ 2.5 cm or marker invisibility. The mean follow-up period was 28.8 (12-45) months.

RESULTS

Suture failure was observed less frequently in the tendon-to-bone group (18.4%) than in the tendon-to-tendon group (65%; p < 0.001). Failure mostly occurred within two weeks post-operatively: 93.8% for tendon-to-bone repair (p < 0.001) and 90.4% for tendon-to-tendon repair (p = 0.025). The dislocation rate was significantly higher in the tendon-to-tendon group (7. vs 1.1%; p = 0.041). A significant correlation was observed between suture failure and dislocation (p = 0.013).

CONCLUSIONS

Tendon-to-bone repair is superior to tendon-to-tendon repair based on lower suture failure and dislocation rates.

Continuous Posterior Lumbar Plexus Nerve Block Versus Periarticular Injection with Ropivacaine or Liposomal Bupivacaine for Total Hip Arthroplasty: A Three-Arm Randomized Clinical Trial

BACKGROUND

Debate surrounds the issue of whether peripheral nerve blockade or periarticular infiltration (PAI) should be employed within a contemporary, comprehensive multimodal analgesia pathway for total hip arthroplasty. We hypothesized that patients treated with a continuous posterior lumbar plexus block (PNB) would report less pain and consume less opioid medication than those treated with PAI.

METHODS

This investigator-initiated, independently funded, 3-arm randomized clinical trial (RCT) performed at a single high-volume institution compared postoperative analgesia interventions for elective, unilateral primary total hip arthroplasty: (1) PNB; (2) PAI with ropivacaine, ketorolac, and epinephrine (PAI-R); and (3) PAI with liposomal bupivacaine, ketorolac, and epinephrine (PAI-L) using computerized randomization. The primary outcome was maximum pain during the morning (06:00 to 12:00) of the first postoperative day (POD) on an ascending numeric rating scale (NRS) from 0 to 10. Pairwise treatment comparisons were performed using the rank-sum test, with a p value of <0.017 indicating significance (Bonferroni adjusted). A sample size of 150 provided 80% power to detect a difference of 2.0 NRS units.

RESULTS

We included 159 patients (51, 54, and 54 patients in the PNB, PAI-R, and PAI-L groups, respectively). No significant differences were found with respect to the primary end point on the morning of the first POD (median, 3.0, 4.0, and 3.0, respectively; p > 0.033 for all). Opioid consumption was low and did not differ across groups at any intervals. Median maximum pain on POD 1 was 5.0, 5.5, and 4.0, respectively, and was lower for the PAI-L group than for the PAI-R group (p = 0.006). On POD 2, maximum pain (median, 3.5, 5.0, and 3.5, respectively) was lower for the PNB group (p = 0.014) and PAI-L group (p = 0.016) compared with the PAI-R group. The PAI-L group was not significantly different from the PNB group with respect to any outcomes: postoperative opioid use including rescue intravenous opioid medication, length of stay, and hospital adverse events, and 3-month follow-up data including any complication.

CONCLUSIONS

In this RCT, we found a modest improvement with respect to analgesia in patients receiving PNB compared with those receiving PAI-R, but not compared with those who had PAI-L. Secondary analyses suggested that PNB or PAI-L provides superior postoperative analgesia compared with PAI-R. For primary total hip arthroplasty, a multimodal analgesic regimen including PNB or PAI-L provides opioid-limiting analgesia.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Clinical Considerations for the Use Lower Extremity Arthroplasty in the Elderly

There is an increase in the aging population that has led to a surge of reported cases of osteoarthritis and a greater demand for lower extremity arthroplasty. This article aims to review the current treatment options and expectations when considering lower extremity arthroplasty in the elderly patient with an emphasis on the following subjects: (1) updated clinical guidelines for the management of osteoarthritis in the lower extremity, (2) comorbidities and risk factors in the surgical patient, (3) preoperative evaluation and optimization of the surgical patient, (4) surgical approach and implant selection, and (5) rehabilitation and life after lower extremity arthroplasty.

Can Surgeons Reduce the Risk for Dislocation After Primary Total Hip Arthroplasty Performed Using the Posterolateral Approach?

BACKGROUND

Hip dislocation is one of the most common postoperative complications after total hip arthroplasty (THA). Potential contributors include patient- and surgical-related factors. We performed a retrospective cohort study to identify risk factors for postoperative dislocation in patients receiving THA via the posterolateral approach.

METHODS

We assessed 1326 consecutive primary THAs performed between 2010 and 2015. Patient information was documented, and plain radiographic films were used to evaluate cup positioning, hip offset, and hip length change. A multiple logistic regression was used to identify risk factors for dislocation. Follow-up was coordinated by the Danish National Patient Registry.

RESULTS

Age and American Society of Anesthesiologists scores were higher in dislocating THA compared with those in the nondislocating THA. Cup anteversion was less in dislocating THA compared with that in nondislocating THA. Independent risk factors for cup dislocation were increased age, body mass index <25 and >30 kg/m², and leg shortening of >5 mm.

CONCLUSION

Surgeons should aim for a shortening of leg length <5 mm to reduce the risk of postoperative dislocation in primary THA. Although anteversion was reduced for dislocating THA, there is likely no universal safe zone for cup positioning. Hip stability is multifactorial, and optimal cup positioning may vary from patient to patient.

Risk factors for post-operative periprosthetic fractures following primary total hip arthroplasty with a proximally coated double-tapered cementless femoral component

AIMS

The aim of this study was to identify patient- and surgery-related risk factors for sustaining an early periprosthetic fracture following primary total hip arthroplasty (THA) performed using a double-tapered cementless femoral component (Bi-Metric femoral stem; Biomet Inc., Warsaw, Indiana).

PATIENTS AND METHODS

A total of 1598 consecutive hips, in 1441 patients receiving primary THA between January 2010 and June 2015, were retrospectively identified. Level of pre-operative osteoarthritis, femoral Dorr type and cortical index were recorded. Varus/valgus placement of the stem and canal fill ratio were recorded post-operatively. Periprosthetic fractures were identified and classified according to the Vancouver classification. Regression analysis was performed to identify risk factors for early periprosthetic fracture.

RESULTS

The mean follow-up was 713 days (1 to 2058). A total of 48 periprosthetic fractures (3.0%) were identified during the follow-up and median time until fracture was 16 days, (interquartile range 10 to 31.5). Patients with femoral Dorr type C had a 5.2 times increased risk of post-operative periprosthetic fracture compared with type B, while female patients had a near significant two times increased risk over time for post-operative fracture.

CONCLUSION

Dorr type C is an independent risk factor for early periprosthetic fracture, following THA using a double tapered cementless stem such as the Bi-Metric. Surgeons should take bone morphology into consideration when planning for primary THA and consider using cemented femoral components in female patients with poor bone quality. Cite this article: Bone Joint J 2017;99-B:451-7.

Osteolysis of the Greater Trochanter Caused by a Foreign Body Granuloma Associated with the Ethibond® Suture after Total Hip Arthroplasty

The present case shows a case of progression of osteolysis of the greater trochanter caused by a foreign body granuloma associated with the number 5 Ethibond suture in cementless THA with the direct lateral approach that was completely healed by removal of the Ethibond suture. A 55-year-old Japanese woman with secondary osteoarthritis caused by acetabular dysplasia underwent left cementless THA with the direct lateral approach. After setting of the total hip prosthesis, the gluteus medius muscle and vastus lateralis muscle were reattached to the greater trochanter through two bone tunnels using number 5 Ethibond EXCEL sutures. The left hip pain disappeared after surgery, but the bone tunnels enlarged gradually and developed osteolysis at 10 weeks. The removal of the Ethibond sutures and debridement improved the osteolysis. Histological examination showed the granuloma reaction to a foreign body with giant cell formation. The Ethibond suture has the lowest inflammatory tissue reaction and relatively high tension strength among nonabsorbable suture materials. However, number 5 Ethibond has the potential to cause osteolysis due to a foreign body granuloma, as in the present case.

Ambulatory Ability and Personal Independence After Hemiarthroplasty and Total Arthroplasty for Intracapsular Hip Fracture: A Prospective Comparative Study

BACKGROUND

Total hip arthroplasty (THA) has not only been associated with best functional outcomes but also with higher dislocation risk when compared with bipolar hemiarthroplasty (HA). The functionality and activities of daily living (ADL) of patients treated with THA or HA for intracapsular hip fracture (IHF) have been scarcely investigated in comparison with the preoperative status.

METHODS

Two comparable groups of 60 patients with an IHF who had undergone either THA or bipolar HA were created matching several preoperative characteristics. Matched variables included age, gender, body mass index, surgical delay, American Society of Anesthesiologists class, comorbidity, cognitive status, educational status, prefracture functional status, and radiographic fracture classification. Patients were prospectively followed up for 1 year using telephone interviews.

RESULTS

The ambulatory ability (5-item scale) and ADL Index significantly decreased in both the groups in comparison with the prefracture status at the 4-month and 1-year follow-up. The need for walking aids (5-item scale) at 4 months was significantly higher among patients who had undergone HA. Lower scores on the ADL Index were recorded among patients with HA in comparison with those with THA at 4 months and 1 year. No significant differences in ambulatory ability, complication rate, and mortality were detected between the 2 groups although HA and THA were associated with a tendency to a higher prevalence of general and local complications, respectively.

CONCLUSION

THA provides better short-term results in terms of ADLs and allows early discontinuation in the use of walking aids as compared with bipolar HA in elderly cognitively intact patients with IHF.

Limited benefits of the direct anterior approach in primary hip arthroplasty: A prospective single centre cohort study

BACKGROUND

Since years a discussion is held on the best approach to perform total hip replacement (THR). Risk of dislocation, abductor weakness and a possible difference in rehabilitation are mentioned. We performed this study to objectify that the use of the direct anterior approach (DAA) results in a faster rehabilitation after THR compared to the non-DAA (posterolateral and anterolateral) approach.

METHODS

A single centre prospective cohort study was conducted. Pre- and 16-weeks postoperative completed PROMs like the VAS, PSC, GPE and HOOS were analyzed. A leg press and power test were performed. Functional capacity was determined by the TUG and the 6MWT.

RESULTS

A total of 119 patients were included for analysis: 87 in the DAA group, 32 in the non-DAA group. There were no differences in general baseline characteristics. The length of stay was significant (p = .000) shorter in the DAA group. At 16 weeks, the DAA group showed a significant greater improvement with respect to the VAS and HOOS. Also significant differences for all strength, power and functional capacity parameters between the pre- and postoperative measurements were found. A subgroup analysis at 6-weeks postoperative showed significant improvements in the TUG (p = .009) and 6MWT (p = .009) in the DAA group, but not in the non-DAA group.

CONCLUSION

PROMs, strength, power and functional capacity tests show significant improvement in all approaches after THR. There seems to be a small advantage in favour of the DAA, in particular directly postoperative and the first postoperative weeks.

No Difference in Dislocation Seen in Anterior Vs Posterior Approach Total Hip Arthroplasty

BACKGROUND

The direct anterior approach (DAA) for total hip arthroplasty (THA) has rapidly become popular, but there is little consensus regarding the risks and benefits of this approach in comparison with a modern posterior approach (PA).

METHODS

A total of 2147 patients who underwent DAA THA were propensity score matched with patients undergoing PA THA on the basis of age, gender, body mass index, and American Society of Anesthesia classification using data from a state joint replacement registry. Mean age of the matched cohort was 64.8 years, mean body mass index was 29.1 kg/m(2), and 53% were female. Multilevel logistic regression models using generalized estimating equations to control for grouping at the hospital level were used to identify differences in various outcomes.

RESULTS

There was no difference in the dislocation rate between patients undergoing DAA (0.84%) and PA (0.79%) THA. Trends indicating a slightly longer length of stay with the PA and a slightly greater risk of fracture, increased blood loss, and hematoma with the DAA are consistent with previous studies.

CONCLUSION

On the basis of short-term outcome and complication data, neither approach has a compelling advantage over each other, including no difference in the dislocation risk.

Direct Repair of the Superior Band of Bigelow's Ligament After Hip Arthroplasty: a Surgical Technique

BACKGROUND

The posterolateral approach is one of the most common approaches used during hip arthroplasty. A posterior soft tissue repair is necessary to limit the risk of postoperative dislocation. For a trapezoidal capsulotomy, the proximal limb divides the superior band of the iliofemoral ligament (Bigelow's ligament). A transosseous repair frequently leaves a defect in this region, which may elevate the risk for dislocation. The purpose of this article is to describe a simple, rational technique for reinforcing the posterior capsular repair.

DESCRIPTION OF TECHNIQUE

A meticulous exposure of the hip capsule is performed during the posterolateral surgical approach. A trapezoidal capsulotomy is performed. After implantation of the arthroplasty implants, retractors are placed to expose the superior capsule. Prior to transosseous repair of the capsule and short external rotator tendons, the proximal limb of the capsulotomy is reapproximated anatomically and repaired with non-absorbable sutures. If anatomical repair is not possible, leg length and femoral offset should be reassessed carefully.

DISCUSSION

The described modification may further minimize the risk of dislocation following hip arthroplasty, as the superior band of Bigelow's ligament is an additional checkrein to internal and external rotation. This repair provides a secondary intraoperative assessment of leg length and femoral offset to ensure proper biomechanical reconstruction of the hip joint. It is the authors' preferred technique of all hip hemiarthroplasties and total hip arthroplasties, whenever possible.

Evaluation and management of chronic total hip instability

Given the increasing number of total hip arthroplasty procedures being performed annually, it is imperative that orthopaedic surgeons understand factors responsible for instability. In order to treat this potentially complex problem, we recommend correctly classifying the type of instability present based on component position, abductor function, impingement, and polyethylene wear. Correct classification allows the treating surgeon to choose the appropriate revision option that ultimately will allow for the best potential outcome.

Posterior Soft Tissue Repair After Primary THA is Durable at Mid-term Followup: A Prospective MRI Study

BACKGROUND

The enhanced posterior soft tissue repair has reduced the frequency of dislocation after primary THA performed through the posterolateral approach. However, the long-term integrity of the repair is unknown and could influence surgeon choice regarding surgical technique and THA approach.

QUESTIONS/PURPOSES

We asked: (1) What is the durability of the enhanced posterior soft tissue repair at a minimum of 49 months using MRI to evaluate soft tissue to bone integrity? (2) How does the appearance of the posterior soft tissues change during this time? (3) Are there patient characteristics associated with the long-term imaging appearance of the posterior repair?

METHODS

All patients without a contraindication for MRI who were undergoing unilateral primary uncemented THA through a posterior approach between February and May 2005 were eligible for inclusion. Ninety percent consented to participate (36 of 40 patients), and 30 patients were followed prospectively with MRI postoperatively and again at 3 months; of those, 22 (73%; 12 men, 10 women) completed the study by having another MRI study at a minimum of 49 months (mean, 51 months; range, 49-59 months). Each patient underwent metal-artifact-reduction sequence MRI to evaluate the integrity of the posterior soft tissues, which had been repaired anatomically during primary THA at a minimum of 4 years earlier. The results were compared with those of prior MR images obtained immediately after surgery and at 3 months postoperatively. All patients were given a self-reported modified Harris hip score at the time of the most recent MRI study (maximum score = 81).

RESULTS

At latest followup, 21 of 22 (96%) patients had a posterior capsule in contact with bone, and 21 of 22 (96%) had an intact quadratus femoris. Twenty-one patients (96%) had soft tissue or a scar from the piriformis and conjoined tendons in continuity with bone. In these cases, the interface between the piriformis and conjoined tendons and the greater trochanter observed immediately postoperatively and at 3 months postoperatively became filled with hypointense tissue, with signal characteristics similar to tendon. Time from surgery was most associated with changes in native tendon-to-bone distances (p < 0.001) and MRI signal intensity of the repair (p < 0.001).

CONCLUSIONS

At followup of just more than 4 years, the posterior capsule and quadratus femoris most often were healed to bone. In the majority of patients, scar tissue between the piriformis and conjoined tendons and bone matured to achieve orientation and signal intensity resembling native tendon. We believe the enhanced posterior soft tissue repair facilitates this process. Our results provide a plausible explanation for improved postoperative stability observed in patients receiving an enhanced soft tissue repair compared with those in whom a repair is not performed.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Removal of restrictions following primary THA with posterolateral approach does not increase the risk of early dislocation

BACKGROUND AND PURPOSE

Patient education and mobilization restrictions are often used in an attempt to reduce the risk of dislocation following primary THA. To date, there have been no studies investigating the safety of removal of mobilization restrictions following THA performed using a posterolateral approach. In this retrospective non-inferiority study, we investigated the rate of early dislocation following primary THA in an unselected patient cohort before and after removal of postoperative mobilization restrictions.

PATIENTS AND METHODS

From the Danish National Health Registry, we identified patients with early dislocation in 2 consecutive and unselected cohorts of patients who received primary THA at our institution from 2004 through 2008 (n = 946) and from 2010 through 2014 (n = 1,329). Patients in the first cohort were mobilized with functional restrictions following primary THA whereas patients in the second cohort were allowed unrestricted mobilization. Risk of early dislocation (within 90 days) was compared in the 2 groups and odds ratio (OR)-adjusted for possible confounders-was calculated. Reasons for early dislocation in the 2 groups were identified.

RESULTS

When we adjusted for potential confounders, we found no increased risk of early dislocation within 90 days in patients who were mobilized without restrictions. Risk of dislocation within 90 days was lower (3.4% vs 2.8%), risk of dislocation within 30 days was lower (2.1% vs 2.0%), and risk of multiple dislocations (1.8% vs 1.1%) was lower in patients who were mobilized without restrictions, but not statistically significantly so. Increasing age was an independent risk factor for dislocation.

INTERPRETATION

Removal of mobilization restrictions from the mobilization protocol following primary THA performed with a posterolateral approach did not lead to an increased risk of dislocation within 90 days.

An appraisal of the short lateral rotators of the hip joint

The short lateral rotators (piriformis, obturator internus, superior and inferior gemelli, obturator internus, and quadratus femoris) are functionally important muscles, significantly contributing to hip joint stability. They act as "postural muscles", holding the femoral head in the acetabulum during hip movements, thus are frequently monitored in gait analysis and for muscle rehabilitation post-injury. Despite the need to precisely identify and repair these muscles for stability postoperatively, clinical complications have resulted from the inadequate and inconsistent understanding of their morphological and functional anatomy. Furthermore, the short lateral rotators have complex entheses (osteotendinous insertions on bone) and may be subject to overuse injury in sport. This study aims to review the reported morphology of the short lateral rotators in order to ascertain whether discrepancies exist in our understanding of these muscles, and if further investigation is required to aid in gait analysis, clinical management of hip pathologies, and prevention of overuse injuries. Following a literature search strategy, 59 primary references were retrieved from three databases, with additional 26 anatomical textbooks selected for critical evaluation. Numerous inaccuracies and inconsistencies in the anatomical descriptions of the attachments, patterns of innervation and actions exist, and often insufficiently supported by primary findings. There is also a paucity of information regarding the architectural pattern of the muscles, which would be useful in clarifying the function of these dynamic stabilizers of the hip joint. A better anatomical understanding of these muscles will better inform hip reconstruction and lead to improved surgical outcomes by reducing post-operative complications.

Direct anterior versus miniposterior THA with the same advanced perioperative protocols: surprising early clinical results

BACKGROUND

Although some surgeons strongly advocate for one approach over the other, there are few data directly comparing the direct anterior approach with a miniposterior approach for total hip arthroplasty (THA).

QUESTIONS/PURPOSES

Using the same advanced pain and rapid rehabilitation protocols for both groups, we compared the direct anterior and miniposterior approaches with respect to (1) return to activities of daily living at 2 days, 2 weeks, or 2 months; (2) risk of intraoperative or early postoperative complications; and (3) component position.

METHODS

Over a 1-year period we identified all consecutive, primary direct anterior and miniposterior THAs performed by two surgeons at our institution, totaling 242 patients. Of those, 20 did not meet inclusion criteria as a result of prior trauma or surgery about the hip. A total of 222 patients, 126 direct anterior and 96 miniposterior, were retrospectively evaluated. All cases were done by one of two surgeons, one of whom performs THA exclusively through the direct anterior approach and the other who only uses the miniposterior approach. Groups did not differ demographically with mean±SD age 64±12 years, mean body mass index 30±5.7 kg/m2, and 50% female. The same rapid rehabilitation protocols were used with no postoperative hip positioning precautions.

RESULTS

No differences were seen between the two groups in mean length of stay (2.2 days; range, 1-9 days), operative or in-hospital complications, intravenous breakthrough analgesia, stairs, maximum feet walked in-hospital, or percent discharged to home (80% [177 of 222]; all p>0.2). The direct anterior patients had longer mean operative times (114 minutes; range, 60-251 minutes) than the miniposterior patients (mean, 60 minutes; range, 41-113 minutes; p<0.001). The direct anterior group had a higher maximum visual analog scale pain score (5.3 direct anterior; ±2, versus 3.8 MP; ±2; p<0.0001). At 2 weeks, more direct anterior patients required gait aids (92% [116 of 126]) than miniposterior (68% [62 of 96]; p<0.0001). At 8 weeks, direct anterior patients had higher mean Harris hip scores (95 versus 89) but a lower return to work and driving with no difference in their use of gait aids, narcotics, activities of daily living, or walking 0.5 mile. More wound problems occurred in the miniposterior group (p<0.01). With the numbers available, component alignment was not different between the study groups (p>0.05 for all comparisons).

CONCLUSIONS

There was no systematic advantage of direct anterior THA versus miniposterior THA. Contrary to conventional belief and somewhat surprising were the fewer minor wound problems in the direct anterior group and the higher proportion of patients free of gait aids at 2 weeks and back to driving and working at 8 weeks in the miniposterior group. Factors other than surgical approach, perhaps including attentive pain management, patient selection, surgical volume and experience, careful preoperative templating, and rapid rehabilitation protocols, may be more important in terms of influencing early recovery after THA.

LEVEL OF EVIDENCE

Level III, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Anatomical basis for surgical approaches to the hip

The hip joint is one of the most surgically exposed joints in the body. The indications for surgical exposure are numerous ranging from simple procedures such as arthrotomy for joint drainage in infection to complex procedures like revised total hip replacement. Tissue dissections based on sound knowledge of anatomic orientations is essential for best surgical outcomes. In this review, the anatomical basis for the various approaches to the hip is presented. Systematic review of the literature was done by using PubMed, Cochrane, Embase, OVID, and Google databases. Out of the initial 150 articles selected from the the review and selection criteria, only 37 that suited the study were eventually used. Selected articles included case reports, clinical trials, review and research reports. Each of these approaches has various modifications that seek to correct certain difficulties or problems encountered with previous descriptions. An ideal approach for a procedure should be safe and provide satisfactory exposure of the joint. It should avoid bone and soft tissue damage as well as avoid unnecessary devascularization. Among the factors that determine the choice of surgical approach to the hip are the indication for the procedure; the influence of previous surgical incisions as well as the personal preferences and training of the operating surgeon.

The risk of revision due to dislocation after total hip arthroplasty depends on surgical approach, femoral head size, sex, and primary diagnosis. An analysis of 78,098 operations in the Swedish Hip Arthroplasty Register

BACKGROUND AND PURPOSE

The effects of patient-related and technical factors on the risk of revision due to dislocation after primary total hip arthroplasty (THA) are only partly understood. We hypothesized that increasing the femoral head size can reduce this risk, that the lateral surgical approach is associated with a lower risk than the posterior and minimally invasive approaches, and that gender and diagnosis influence the risk of revision due to dislocation.

PATIENTS AND METHODS

Data on 78,098 THAs in 61,743 patients performed between 2005 and 2010 were extracted from the Swedish Hip Arthroplasty Register. Inclusion criteria were a head size of 22, 28, 32, or 36 mm, or the use of a dual-mobility cup. The covariates age, sex, primary diagnosis, type of surgical approach, and head size were entered into Cox proportional hazards models in order to calculate the adjusted relative risk (RR) of revision due to dislocation, with 95% confidence intervals (CI).

RESULTS

After a mean follow-up of 2.7 (0-6) years, 399 hips (0.5%) had been revised due to dislocation. The use of 22-mm femoral heads resulted in a higher risk of revision than the use of 28-mm heads (RR = 2.0, CI: 1.2-3.3). Only 1 of 287 dual-mobility cups had been revised due to dislocation. Compared with the direct lateral approach, minimally invasive approaches were associated with a higher risk of revision due to dislocation (RR = 4.2, CI: 2.3-7.7), as were posterior approaches (RR = 1.3, CI: 1.1-1.7). An increased risk of revision due to dislocation was found for the diagnoses femoral neck fracture (RR = 3.9, CI: 3.1-5.0) and osteonecrosis of the femoral head (RR = 3.7, CI: 2.5-5.5), whereas women were at lower risk than men (RR = 0.8, CI: 0.7-1.0). Restriction of the analysis to the first 6 months after the index procedure gave similar risk estimates.

INTERPRETATION

Patients with femoral neck fracture or osteonecrosis of the femoral head are at higher risk of dislocation. Use of the minimally invasive and posterior approaches also increases this risk, and we raise the question of whether patients belonging to risk groups should be operated using lateral approaches. The use of femoral head diameters above 28 mm or of dual-mobility cups reduced this risk in a clinically relevant manner, but this observation was not statistically significant.