[Minimally invasive surgery in total hip arthroplasty : Surgical technique of the future?]

Direct anterior approach vs. SuperPATH vs. conventional approaches in total hip replacement: A network meta-analysis of randomized controlled trials

BACKGROUND

Two minimally invasive approaches showed some advantages in outcomes compared to conventional approaches (CAs) - the direct anterior approach (DAA) and the supercapsular percutaneously assisted approach in THA (SuperPATH). To the best of our knowledge, these three approaches have never been ranked in a network meta-analysis (NMA) before. Therefore, we conducted a systematic review and NMA of randomized controlled trials comparing short-term outcomes of DAA, SuperPATH and CAs in total hip joint arthroplasty (THA), using CAs as common comparator.

METHODS

A systematic literature search up to February 2021 was performed to identify randomized controlled trials (RCTs) comparing DAA with CAs and SuperPATH with CAs in THA. We measured surgical, functional and radiological outcomes. A NMA, using frequentist methods was performed to assess treatment effects between DAA, SuperPATH and CAs. Information was borrowed from the above-mentioned RCTs, using the CA group as a common comparator.

RESULTS

A total of 24 RCTs involving 2,074 patients met the inclusion criteria, six trials with a level I evidence, 18 trials with level II evidence. SuperPATH reduced operation time (fixed effects model: MD=8.1, 95% CI: 5.7 to 10.4), incision length (fixed effects model: MD=2.7, 95%CI: 2.5 to 2.9; random effects model: MD=4.1, 95%CI: 0.6 to 7.6), intraoperative blood loss (fixed effects model: MD=157, 95%CI: 139.2 to 174.2; random effects model: MD=129, 95%CI: 11.5 to 245.7) and early pain intensity (VAS 1 day postoperatively with a fixed effects model: MD=0.8, 95%CI: 0.4 to 1.2) compared to DAA. The two approaches did not differ in functional outcome and in acetabular cup inclination positioning.

CONCLUSIONS

Our overall findings suggest that short-term outcomes of THA through SuperPATH were superior to DAA and CAs and that short-term outcomes of THA through DAA were superior to CAs.

LEVEL OF EVIDENCE

II; systematic review with level I studies and level II studies.

Comparison of short-term outcomes between direct anterior approach (DAA) and SuperPATH in total hip replacement: a systematic review and network meta-analysis of randomized controlled trials

BACKGROUND

Two minimally invasive approaches showed some advantages in outcomes compared to conventional approaches (CAs)-the direct anterior approach (DAA) and the supercapsular percutaneously assisted approach in THA (SuperPATH). To the best of our knowledge, DAA and SuperPATH have never been compared, neither in clinical studies, nor in a meta-analysis. To conduct a systematic review and network meta-analysis of randomized controlled trials comparing short-term outcomes of DAA and SuperPATH in total hip joint arthroplasty (THA).

METHODS

A systematic literature search up to May 2020 was performed to identify randomized controlled trials (RCTs) comparing SuperPATH with CAs and DAA with CAs in THA. We measured surgical, functional, and radiological outcomes. A network meta-analysis, using frequentist methods, was performed to assess treatment effects between DAA and SuperPATH. Information was borrowed from the above-mentioned RCTs, using the CA group as a common comparator.

RESULTS

A total of 16 RCTs involving 1392 patients met the inclusion criteria, three trials with a level I evidence, 13 trials with a level II evidence. The overall network meta-analysis showed that SuperPATH reduced operation time (fixed effect model: MD = 12.8, 95% CI 9.9 to 15.7), incision length (fixed effect model: MD = 4.3, 95% CI 4.0 to 4.5; random effect model: MD = 4.3, 95% CI 0.2 to 8.4), intraoperative blood loss (fixed effect model: MD = 58.6, 95% CI 40.4 to 76.8), and early pain intensity (VAS 1 day postoperatively with a fixed effect model: MD = 0.8, 95% CI 0.4 to 1.2). The two approaches did not differ in acetabular cup positioning angles and in functional outcome.

CONCLUSIONS

Our overall findings suggested that the short-term outcomes of THA through SuperPATH were superior to DAA. SuperPATH showed better results in decreasing operation time, incision length, intraoperative blood loss, and early pain intensity. DAA and SuperPATH were equal in functional outcome and acetabular cup positioning.

[Gluteal insufficiency]

Gluteal insufficiency or hip abductor mechanism deficiency mainly following (revision) total hip replacement is associated with highly painful complaints and severe suffering of patients. It represents a great diagnostic and therapeutic challenge. Differentiated conservative treatment pathways, open surgical and endoscopic anatomic repair techniques with intact gluteal musculature and muscle transfer are available as salvage procedures for chronic not anatomically reconstructable mass ruptures. A stepwise diagnostic and therapeutic approach is required for restoration of the quality of life and painless or almost painless mobility of affected patients in occupation and daily life.

Navigation is Equal to Estimation by Eye and Palpation in Preventing Psoas Impingement in THA

BACKGROUND

Iliopsoas tendon impingement is one possible reason for persistent groin pain and diminished functional outcome after THA. So far, estimation by eye and palpation is the standard procedure to intraoperatively assess the distance of the cup to the anterior rim. However, novel technologies such as imageless navigation enable intraoperative measurements of the cup in relation to the psoas tendon and bony landmarks.

QUESTIONS/PURPOSES

We asked whether psoas impingement (1) can be reduced using imageless navigation compared with the standard technique and (2) is associated with specific patient characteristics. Furthermore, we investigated (3) if anterior cup protrusion (overhang) is associated with lower outcome scores for pain and function.

METHODS

The current study is a reanalysis of data from a randomized controlled trial evaluating navigation for THA; 135 patients were randomized for surgery with or without the use of imageless navigation. The risk for anterior protrusion of the cup above the acetabular rim and thus potential psoas impingement, defined as an overhang of the cup above the anterior acetabular rim as measured on postoperative CT, was either controlled with the help of navigation or standard control by eye and palpation intraoperatively. Postoperatively, the anterior protrusion of the cup above the acetabular rim was measured on three-dimensional (3-D) CT by a blinded, external institute. In addition to patient-related outcome measures, the Harris hip score, Hip disability and Osteoarthritis Outcome Score, and EuroQol were obtained 1 year postoperatively. Altogether 123 data sets were available for primary analysis and 115 were available for 1-year followup.

RESULTS

There was no difference, with the numbers available, between the navigated and the control groups in terms of the mean distance of the cup below the anterosuperior acetabular rim (3.9 mm; -5.3 to 12.6 mm versus 4.4 mm; -7.9 to 13.7 mm; p = 0.72) or the anteroinferior acetabular rim (4.7 mm; -6.2 to 14.8 mm versus 4.2 mm; -7.1 to 16.3 mm; p = 0.29). There was no difference, with the numbers available, in terms of the proportion of cups with anterior overhang (7%, four of 57 versus, 15%, 10 of 66; p = 0.16), respectively. After controlling for potential confounding variables such as cup inclination, cup size, patient age, BMI, stage of arthritis, and length of skin incision, we found cup anteversion (hazard ratio [HR], 0.87; 95% CI, 0.81-0.93; p < 0.001) and female sex (HR, 3.88; 95% CI, 1.01-14.93; p = 0.049) were associated with a propensity to potential psoas impingement. With the numbers available, there were no differences observed in clinical scores between groups with and without anterior cup protrusion.

CONCLUSIONS

We found no differences between imageless navigation and estimation by eye and palpation in preventing potential psoas impingement. Despite the comparable clinical outcome for patients with and without cup protrusion, the orthopaedic surgeon should be especially aware of propensity for psoas impingement in women.

LEVEL OF EVIDENCE

Level II, therapeutic study.

Radiographic Assessment of Femoral Stem Torsion in Total Hip Arthroplasty-A Comparison of a Caput-Collum-Diaphyseal Angle-Based Technique With the Budin View

BACKGROUND

Correct assessment of femoral stem torsion is crucial in total hip arthroplasty (THA). In this study, we aimed to compare a recently published novel method based on anteroposterior (AP) hip radiographs using the projected caput-collum-diaphyseal (CCD) angle (AP CCD) with the modified posteroanterior Budin view.

METHOD

AP radiographs, modified Budin views, and 3-dimensional computed tomography (3D-CT) images were obtained in 30 patients after minimally invasive, cementless THA. Radiographic measurements performed by 4 observers twice in a 6-week interval were compared with 3D-CT measurements. Furthermore, correlations between the radiographic deviation to 3D-CT and patient specific characteristics were evaluated.

RESULTS

We found a mean difference of 2.2 ± 6.8° between AP CCD and 3D-CT measurements of femoral stem torsion and -0.5 ± 4.2° between the modified Budin view and 3D-CT. We found a high correlation between mean radiographic and 3D-CT stem torsion (r = 0.78, P < .001 for AP CCD and r = 0.84, P < .001 for Budin view). The observers had excellent agreements within (intraclass correlation coefficient, ≥0.88 for AP CCD and intraclass correlation coefficient, ≥0.94 for Budin view) and between (mean concordance correlation coefficient, ≥0.79 for AP CCD and concordance correlation coefficient, ≥0.86 for Budin view) their radiographic measurements.

CONCLUSION

Both radiographic methods enable a simple orientation and a practical conventional radiographic estimation of stem torsion on hip radiographs after THA. However, CT remains the golden standard for exact estimation of stem torsion.

Influence of minimally invasive total hip replacement on hip reaction forces and their orientations

Minimally invasive surgery (MIS) is becoming increasingly popular. Supporters claim that the main advantages of MIS total hip replacement (THR) are less pain and a faster rehabilitation and recovery. Critics claim that safety and efficacy of MIS are yet to be determined. We focused on a biomechanical comparison between surgical standard and MIS approaches for THR during the early recovery of patients. A validated, parameterized musculoskeletal model was set to perform a squat of a 50th percentile healthy European male. A bilateral motion was chosen to investigate effects on the contralateral side. Surgical approaches were simulated by excluding the incised muscles from the computations. Resulting hip reaction forces and their symmetry and orientation were analyzed. MIS THR seemed less influential on the symmetry index of hip reaction forces between the operated and nonoperated leg when compared to the standard lateral approach. Hip reaction forces at peak loads of the standard transgluteal approach were 24% higher on the contralateral side when compared to MIS approaches. Our results suggest that MIS THR contributes to a greater symmetry of hip reaction forces in absolute value as well as force-orientation following THR.

Fluoroscopy and imageless navigation enable an equivalent reconstruction of leg length and global and femoral offset in THA

BACKGROUND

Restoration of biomechanics is a major goal in THA. Imageless navigation enables intraoperative control of leg length equalization and offset reconstruction. However, the effect of navigation compared with intraoperative fluoroscopy is unclear.

QUESTIONS/PURPOSES

We asked whether intraoperative use of imageless navigation (1) improves the relative accuracy of leg length and global and femoral offset restoration; (2) increases the absolute precision of leg length and global and femoral offset equalization; and (3) reduces outliers in a reconstruction zone of ± 5 mm for leg length and global and femoral offset restoration compared with intraoperative fluoroscopy during minimally invasive (MIS) THA with the patient in a lateral decubitus position.

METHODS

In this prospective study a consecutive series of 125 patients were randomized to either navigation-guided or fluoroscopy-controlled THA using sealed, opaque envelopes. All patients received the same cementless prosthetic components through an anterolateral MIS approach while they were in a lateral decubitus position. Leg length, global or total offset (representing the combination of femoral and acetabular offset), and femoral offset differences were restored using either navigation or fluoroscopy. Postoperatively, residual leg length and global and femoral offset discrepancies were analyzed on magnification-corrected radiographs of the pelvis by an independent and blinded examiner using digital planning software. Accuracy was defined as the relative postoperative difference between the surgically treated and the unaffected contralateral side for leg length and offset, respectively; precision was defined as the absolute postoperative deviation of leg length and global and femoral offset regardless of lengthening or shortening of leg length and offset throughout the THA. All analyses were performed per intention-to-treat.

RESULTS

Analyzing the relative accuracy of leg length restoration we found a mean difference of 0.2 mm (95% CI, -1.0 to +1.4 mm; p = 0.729) between fluoroscopy and navigation, 0.2 mm (95 % CI, -0.9 to +1.3 mm; p = 0.740) for global offset and 1.7 mm (95 % CI, +0.4 to +2.9 mm; p = 0.008) for femoral offset. For the absolute precision of leg length and global and femoral offset equalization, there was a mean difference of 1.7 ± 0.3 mm (p < 0.001) between fluoroscopy and navigation. The biomechanical reconstruction with a residual leg length and global and femoral offset discrepancy less than 5 mm and less than 8 mm, respectively, succeeded in 93% and 98%, respectively, in the navigation group and in 54% and 95%, respectively, in the fluoroscopy group.

CONCLUSIONS

Intraoperative fluoroscopy and imageless navigation seem equivalent in accuracy and precision to reconstruct leg length and global and femoral offset during MIS THA with the patient in the lateral decubitus position.

Development and evaluation of an image-free computer-assisted impingement detection technique for total hip arthroplasty

Periprosthetic or bony impingement in total hip arthroplasty (THA) has been correlated to dislocation, increased wear, reduced postoperative functionality with pain and/or decreased range of motion (ROM). We sought to study the accuracy and assess the reliability of measuring bony and periprosthetic impingement on a virtual bone model prior to the implantation of the acetabular cup with the help of image-free navigation technology in an experimental cadaver study. Impingement-free ROM measurements were recorded during minimally invasive, computer-assisted THA on 14 hips of 7 cadaveric donors. Preoperatively and postoperatively the donors were scanned using computed tomography (CT). Impingement-free ROM on three-dimensional CT-based models was then compared with corresponding, intraoperative navigation models. Bony/periprosthetic impingement can be detected with a mean accuracy limit of below 5° for motion angles, which should be reached after THA for activities of daily living with the help of image-free navigation technology.

[MRI-based measurement of muscle damage after minimally invasive hip arthroplasty]

Muscle trauma in minimally invasive hip arthroplasty using a direct anterior approach was assessed by magnetic resonance imaging (MRI) in 25 patients preoperatively, as well as 6 months after total hip replacement. The MRI evaluation included the measurement of changes in muscle cross-sectional area (CSA = atrophy) and fatty infiltration of the muscles. Using MRI, preoperatively existing and operatively caused muscle tissue damage could be detected by assessing changes in muscle CSA and fatty infiltration. Even preoperatively, a muscular atrophy and fatty infiltration could be demonstrated in the diseased hip. Using the minimally invasive direct anterior approach, a postoperative significantly reduced CSA and significantly increased fatty degeneration was detected for the M. tensor fasciae latae and the M. glutaeus minimus. No increased damage of the M. glutaeus medius could be detected.

[Clinical results of minimally invasive total hip arthroplasty]

AIM

This article presents an analysis and review of recent literature with a focus on clinical results after minimally invasive (MIS) total hip arthroplasty (THA) and with special attention to the different approaches currently used.

METHODS

An online database (Medline) search for clinical trials after THA between 2007 and 2011 was performed with a special focus on prospective controlled randomized trials focusing on THA with a MIS approach. The data were analyzed for pain, blood loss, complications, gait analysis, Harris hip and other scores.

RESULTS

A total of 24 studies (19 comparative studies) were included in this study with a total of 801 MIS THA cases and 695 conventionally operated hips. Almost every study showed superior results for the MIS group with respect to postoperative pain, blood loss and rehabilitation but these advantages almost totally disappeared after 3-6 months. The complication rate was comparable in both groups. After 3-6 months the clinical scores, such as the Harris hip score did not show any differences between conventional and MIS groups.

CONCLUSIONS

In this present study all MIS approaches showed advantages over the conventional surgical approach but these benefits disappeared after 3-6 months. With comparable risks for complications, MIS surgical approaches are superior in the early postoperative phase and rehabilitation.

[Postoperative rehabilitation after minimally invasive total hip arthroplasty]

Currently more than 150,000 total hip arthroplasties (THA) are performed in Germany each year. Despite limited financial resources approximately 50% of these patients participate in a standardized inpatient rehabilitation program. This report reflects own experiences with patients after a minimally invasive approach for THA compared to others with conventional procedures, in context with findings from the literature. Rehabilitation and convalescence in patients with a minimally invasive approach for THA seem to have advantages especially in the first weeks after surgery, with manageable complications and socioeconomic improvements compared to conventional approaches.