The science of minimally invasive total hip arthroplasty

Assessment of Patient Satisfaction and Outcomes After Outpatient Joint Arthroplasty in Academic Medical Centers

Background

There is limited literature evaluating patient satisfaction and outcomes after outpatient joint arthroplasty procedures in academic medical centers (AMCs). The aims of this study are to determine: (1) patients' desires to repeat their procedures and be discharged on the same day, (2) patient-reported outcome measures (PROMs), (3) time to discharge, (4) readmission rates, and (5) factors that predict PROMs in patients undergoing outpatient joint arthroplasty in AMCs.

Methods

A prospective survey was completed by 66 total hip arthroplasty (THA), 35 total knee arthroplasty (TKA), and 180 unicondylar knee arthroplasty (UKA) outpatients who underwent surgery from May 2018 to December 2020 in 2 AMCs. The survey consisted of questions regarding hip or knee PROMs (Hip Disability and Osteoarthritis Outcome Score for Joint Replacement, and Knee Injury and Osteoarthritis Outcome Score for Joint Replacement), satisfaction with outpatient procedures and discharges, and reasons for readmissions. Linear regression analysis was conducted with statistical significance set at P < .05.

Results

100% of THA, 93.8% of TKA, and 93.0% of UKA outpatients stated that they would re-elect to undergo their respective procedure. Furthermore, 94% of THA, 81% of TKA, and 95% of UKA patients stated they would like same-day discharge again. THA, TKA, and UKA patients reported respective mean PROM scores of 94.7, 89.9, and 86.1. Readmission rates were 1.5%, 0.0%, and 0.5%, for THA, TKA, and UKA, respectively.

Conclusions

Patients who underwent outpatient joint arthroplasty procedures at 2 AMCs experienced minimal readmissions and reported a high desire to repeat their outpatient procedures.

The ABLE Anterior-Based Muscle-Sparing Approach: A Safe and Effective Option for Total Hip Arthroplasty

Background

The direct anterior and posterior approaches are well-researched options in total hip arthroplasty (THA). The less-studied anterior-based muscle-sparing approach, also known as the ABLE advanced anterior approach, centers on minimizing surgical trauma and medical costs while maintaining or improving patient outcomes.

Material and methods

THAs performed using the ABLE approach by 3 surgeons at a single institution between January 2013 and August 2020 were retrospectively assessed for outcomes pertaining to safety and performance intraoperatively, perioperatively, and postoperatively. Additionally, intraoperative and postoperative complications were evaluated, and patient-reported outcome measures and radiographic outcomes out to 1-year follow-up.

Results

There were 6251 THAs (5433 patients) eligible for inclusion. The mean surgical time was 65 minutes, mean intraoperative blood loss was 204 mL, and the transfusion rate was 0.5%. Patients had a mean length of stay of 1.4 days. Overall, 93.4% of patients were discharged home, 1.9% visited the emergency department within 30 days, and 2.9% had an unplanned readmission to the hospital within 90 days. The overall major surgical complication rate was 1.18%, with a dislocation rate of 0.13%, a deep infection rate of 0.19%, and a postoperative periprosthetic fracture rate of 0.37%.

Conclusions

The minimally invasive ABLE approach is a safe and effective surgical approach for patients undergoing THA. It can be performed efficiently and with limited complications, making it an appealing option for surgeons to utilize during this era of value-based care.

Minimally Invasive Intermuscular Approaches Versus Conventional Approaches in Total Hip Arthroplasty: A Systematic Review and Meta-Analysis

BACKGROUND

To date, the literature has not yet revealed superiority of Minimally Invasive (MI) approaches over conventional techniques. We performed a systematic review to determine whether minimally invasive approaches are superior to conventional approaches in total hip arthroplasty for clinical and functional outcomes. We performed a meta-analysis of level 1 evidence to determine whether minimally invasive approaches are superior to conventional approaches for clinical outcomes.

METHODS

All studies comparing MI approaches to conventional approaches were eligible for analysis. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were adhered to throughout this study. Registries were searched using the following MeSH terms: 'minimally invasive', 'muscle-sparing', 'THA', 'THR', 'hip arthroplasty' and 'hip replacement'. Locations searched included PubMed, the Cochrane Library, ClinicalTrials.gov, the European Union (EU) clinical trials register and the International Clinical Trials Registry Platform (World Health Organisation).

RESULTS

Twenty studies were identified. There were 1,282 MI total hip arthroplasty (THAs) and 1,351 conventional THAs performed. There was no difference between MI and conventional approaches for all clinical outcomes of relevance including all-cause revision (P = .959), aseptic revision (P = .894), instability (P = .894), infection (P = .669) and periprosthetic fracture (P = .940). There was also no difference in functional outcome at early or intermediate follow-up between the two groups (P = .38). In level I studies exclusively, random-effects meta-analysis demonstrated no difference in aseptic revision (P = .461) and all other outcomes between both groups.

CONCLUSION

Intermuscular MI approaches are equivalent to conventional THA approaches when considering all-cause revision, aseptic revision, infection, dislocation, fracture rates and functional outcomes. Meta-analysis of level 1 evidence supports this claim.

Achievement of optimal implant alignment using taper wedge stems with cup-first THA through the MIS antero-lateral approach

PURPOSE

Combined anteversion (CA) technique (stem-first procedure) has become generally accepted as an ideal means to achieve optimal CA value in THA. However, we hypothesized that CA technique for patients with various native femoral anteversions could pose a risk of anterior or posterior cup protrusion. In the present study, we examined whether it is possible to use the taper wedge stem to change the stem version to achieve optimal CA while avoiding cup protrusions with the cup-first procedure through minimally invasive (MIS) antero-lateral approach.

METHODS

Eighty-one patients underwent cup-first THA with a taper wedge stem. The acetabular cup was placed following the preoperative planning of the cup alignment to avoid anterior cup protrusions using CT-based navigation. Following the CA theory, anteversion of the taper wedge stem was changed to the target anteversion from the patient's native femoral anteversion. The native femoral anteversion, the change in version angle of the stem, postoperative CA and the length of anterior cup protrusions were evaluated in postoperative CT measurements.

RESULTS

The native femoral anteversion averaged 25.7° ± 8.9° (range 8°-45°). Cases with increased and decreased stem anteversion were observed in 42 hips (51.8%) and 33 hips (40.7%), respectively. The amount of increased and decreased version angles averaged 7.7° ± 4.8° (range 2°-21°) and 7.8° ± 5.1° (range 2°-20°), respectively. Postoperative CA values averaged 36.7° ± 3.4° (range 29.4°-44.2°) and anterior cup protrusion length averaged 2.0 mm ± 2.6 mm (0 ~ 8.8 mm) in axial view and 0.4 mm ± 1.0 mm (0 ~ 3.6 mm) in sagittal view. Anterior cup protrusion of more than 10 mm was not observed in any hips.

CONCLUSION

This procedure can be considered as an option to achieve optimal CA anteversion while avoiding anterior cup protrusion in THA.

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.

Computed tomography for preoperative planning in total hip arthroplasty: what radiologists need to know

The number of total hip arthroplasties is continuously rising. Although less invasive surgical techniques, sophisticated component design, and intraoperative navigation techniques have been introduced, the rate of peri- and postoperative complications, including dislocations, fractures, nerve palsies, and infections, is still a major clinical problem. Better patient outcome, faster recovery and rehabilitation, and shorter operation times therefore remain to be accomplished. A promising strategy is to use minimally invasive techniques in conjunction with modular implants, aimed at independently reconstructing femoral offset and leg length on the basis of highly accurate preoperative planning. Plain radiographs have clear limitations for the correct estimation of hip joint geometry and bone quality. Three-dimensional assessment based on computed tomography (CT) allows optimizing the choice and positions of implants and anticipating difficulties to be encountered during surgery. Postoperative CT is used to monitor operative translation and plays a role in arthroplastic quality management. Radiologists should be familiar with the needs of orthopedic surgeons in terms of CT acquisition, post-processing, and data transfer. The CT protocol should be optimized to enhance image quality and reduce radiation exposure. When dedicated orthopedic CT protocols and state-of-the-art scanner hardware are used, radiation exposure can be decreased to a level just marginally higher than that of conventional preoperative radiography. Surgeons and radiologists should use similar terminology to avoid misunderstanding and inaccuracies in the transfer of preoperative planning.

Is limited incision better than standard total hip arthroplasty? A meta-analysis

BACKGROUND

The literature comparing limited incision and standard incision THAs is confusing regarding whether limited incision THA improves short-term recovery without compromising long-term durability and survival. Further, previously published meta-analyses cannot conclude that limited incision THA is better. With new data, we seek to discover if the answers now exist.

PURPOSE

We used meta-analysis to compare surgical and hospitalization data, clinical outcomes, and complication rates, and thus (1) confirm whether limited incision THA is at least comparable to standard incision THA; and (2) determine whether limited incision THA is an improvement over standard incision THA.

METHODS

The PubMed database was searched using the terms "minimally", "invasive", and "total hip". Inclusion was limited to studies directly comparing limited incision with standard incision THA and reporting effect sizes.

RESULTS

We identified 418 articles. Of these 11 provided background information and 30 provided data (3548 THAs) for the systematic review. Limited incision THA was better than standard incision THA in four measures: length of hospitalization (6 versus 7 days), VAS pain at discharge (2 versus 4), blood loss (421 mL versus 494 mL), and the Harris hip score at 3 months postoperation (90 versus 84). There were no outcomes for which standard incision was better. There was no major difference in the rate of complications.

CONCLUSIONS

Short-term recovery favors limited incision over standard incision THA. The lack of consistent reporting for surgical outcomes, clinical outcomes, and complications continues to create difficulties when comparing limited and standard incision THAs.

A comparison of a less invasive piriformis-sparing approach versus the standard posterior approach to the hip

We undertook a randomised controlled trial to compare the piriformis-sparing approach with the standard posterior approach used for total hip replacement (THR). We recruited 100 patients awaiting THR and randomly allocated them to either the piriformis-sparing approach or the standard posterior approach. Pre- and post-operative care programmes and rehabilitation regimes were identical for both groups. Observers were blinded to the allocation throughout; patients were blinded until the two-week assessment. Follow-up was at six weeks, three months, one year and two years. In all 11 patients died or were lost to follow-up.

There was no significant difference between groups for any of the functional outcomes. However, for patients in the piriformis-sparing group there was a trend towards a better six-minute walk test at two weeks and greater patient satisfaction at six weeks. The acetabular components were less anteverted (p = 0.005) and had a lower mean inclination angle (p = 0.02) in the piriformis-sparing group. However, in both groups the mean component positions were within Lewinnek’s safe zone. Surgeons perceived the piriformis-sparing approach to be significantly more difficult than the standard approach (p = 0.03), particularly in obese patients.

In conclusion, performing THR through a shorter incision involving sparing piriformis is more difficult and only provides short-term benefits compared with the standard posterior approach.

Recent advances in designs, approaches and materials in total knee replacement: literature review and evidence today

Ever since Themistocles Gluck described the use of an ivory cup as a tibial hemiarthroplasty in 1894, knee arthoplasty has continued to evolve. Both human ingenuity and intensive clinical research has led to an improved understanding of biomaterials and knee kinematics, resulting in the modern total knee replacement which has enjoyed such a clinical and commercial success. As it increases in popularity, attempts to improve knee arthroplasty have been driven by demands for improved function and implant survival, particularly in younger, more demanding patients. Research continues to see if advances in implant instrumentation, materials and design will translate into improved clinical outcomes and longevity.

Comparison of primary total hip replacements performed with a direct anterior approach versus the standard lateral approach: perioperative findings

Background

Given the increasing demand for tissue-sparing surgery, the surgical approach is the subject of lively debate in total hip replacement. The aim of this paper is to compare the efficacy of the minimally invasive direct anterior approach and the standard lateral approach to total hip replacement surgery by observing intra- and perioperative outcomes.

Materials and methods

The authors conducted a retrospective study on a group of 419 consecutive patients undergoing total hip replacement for coxarthrosis. The patients were divided into a first group (A) of 198 patients who had surgery with the standard lateral approach, and a second control group (B) of 221 patients who had the same procedure via the minimally invasive direct anterior approach. Assessment of the two groups considered the following perioperative parameters: length of the surgical procedure, intraoperative complications, intra- and postoperative blood loss, postoperative pain, postoperative nausea and vomiting, length of stay, and type of discharge.

Results

The two groups were homogeneous when compared in relation to mean age, sex and body weight. The minimally invasive direct anterior approach was performed within an acceptable time (89 ± 19 min vs. 81 ± 15 min) and with modest blood loss (3.1 ± 0.9 g/dL vs. 3,5 ± 1 g/dL). Patients experienced less pain (1.4 ± 1.5 NRS score vs. 2.5 ± 2 NRS score), and PONV affected only 5% versus 10% of cases. Times to discharge were shorter (7 ± 2 days vs. 10 ± 3.5 days), and 58.4% versus 11.6% of patients were discharged to home.

Conclusions

In our study, patients treated with a minimally invasive direct anterior approach had a better perioperative outcome than patients treated with the lateral approach. The longer time of surgery for the minimally invasive direct anterior approach may be attributed to the learning curve. Further studies are necessary to investigate the advantages of a minimally invasive direct anterior approach in terms of clinical results in the short and long run.

No strength or gait benefit of two-incision THA: a brief followup at 1 year

BACKGROUND

Using comprehensive gait analysis and strength testing, we previously investigated the early (2-month) functional outcome after THA using two-incision and mini-posterior surgical approaches and found an advantage for the mini-posterior approach. Benefits included improved muscle strength, a less antalgic gait, and better hip function as reflected by changes in hip moments during level walking and stair climbing. We questioned how these differences in function would fare with longer followup.

QUESTIONS/PURPOSES

We determined whether the observed early functional advantages for the mini-posterior technique over the two-incision technique were still present 1 year postoperatively.

PATIENTS AND METHODS

We prospectively enrolled 22 patients with primary degenerative arthritis of the hip; of these, 21 completed gait and strength testing at 2 months, and 19 completed comprehensive gait and strength testing at 1 year (11 two-incision hips, eight mini-posterior hips). The 19 patients included 11 men and eight women with a mean age of 65 years (range, 40-85 years) and a mean (BMI) of 29 (range, 21-39).

RESULTS

At 1 year postoperatively, the patients who had the mini-posterior THA had greater improvement in hip flexion strength and internal rotation strength, greater increase in hip flexor internal moment, and greater increase in single-leg stance time on level ground over the patients who had the two-incision THA.

CONCLUSIONS

Compared with the two-incision approach, patients undergoing mini-posterior THA had persistently better function, including hip flexor and internal rotator muscle strength, hip flexor internal moment, and single-leg stance during level walking.

LEVEL OF EVIDENCE

Level II, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Age-related appearance of muscle trauma in primary total hip arthroplasty and the benefit of a minimally invasive approach for patients older than 70 years

Old age is frequently associated with a poorer functional outcome after THA. This might be based upon muscular damage resulting from surgical trauma. Minimally invasive approaches have been widely promoted on the basis of the muscle sparing effect. The aim of the study was to evaluate of the functional outcome and the grade of fatty muscle atrophy of the gluteus medius muscle by magnetic-resonance-imaging (MRI) in patients undergoing minimally invasive or traditional THA. Forty patients (21 female, 19 male) underwent THA either via a modified direct lateral (mDL) or a minimally invasive anterolateral (ALMI) approach. Patients were evaluated clinically and by MRI in terms of age (< or ≥70 y) preoperatively and at three and 12 months postoperatively. The Harris hip score and Trendelenburg's sign were recorded and a survey of a pain (using a numeric rating scale of 0-10) and satisfaction score (using a numeric rating scale of 1-6) was performed. Fatty atrophy (FA) of gluteus medius muscle was rated by means of a five-point rating scale (0 indicates no fat and 4 implies more fat than muscle). Younger patients reached a significantly higher Harris hip score, lower pain score and lower rate of positive Trendelenburg's sign accompanied by a significantly lower rate of postoperative FA (P = 0.03; young: FA (MW) = (preop. / 3 / 12 months), 0.15 / 0.7 / 0.7; old: FA (MW) = 0.18 / 1.3 / 1.36). Older patients with an mDL-approach had the significantly lowest clinical scores, the highest rate of positive Trendelenburg's sign and also the highest rate of fatty atrophy (P = 0.03; FA (old) mDL: 1.8; ALMI: 0.7). Interestingly, no influence of the approach could be detected within the younger group. Patients older than 70 years had a poorer functional outcome and a higher postoperative extent of FA when compared to younger patients, which must be based upon a higher vulnerability and a reduced regenerative capacity of their skeletal muscle. Through a minimally invasive approach the muscle trauma in older patients can be effectively reduced and thus the functional outcome significantly improved. Incision and detachment of tendons and muscles should be strictly avoided.

Recent developments in total hip replacements: cementation, articulation, minimal-invasion and navigation

Total hip replacement is a commonly performed procedure with good results. The implants could be cemented or cementless, and there has been a resurgence of resurfacing procedures. It is important that special consideration is given to the choice of the material used at the bearing surfaces. There have been many developments in recent years that influence our choice of implant and have shaped our practice, including minimally invasive surgery and computer-assisted surgery. This article aims to provide an overview of these developments.

Outpatient total hip arthroplasty

Patients younger than 65 years were studied to determine what percentage of patients would enroll in a study of outpatient total hip arthroplasty, its safety, and benefits of the program. Of 192 eligible patients, 69 (36%) enrolled, and 53 (77%) of these went home the same day of surgery. Of 53, 44 maintained a diary for the first 3, weeks and 52 completed a satisfaction questionnaire at 6 weeks. Patients were followed for 6 months for occurrence of complications. There were no medical readmissions. Of 52 patients who completed a 6 week questionnaire, 50 (96%) were satisfied with the decision to have outpatient total hip arthroplasty. There were no objective physical benefits identified. This study reports the distribution of acceptance and completion of same day discharge for patients with total hip arthroplasty in a metropolitan population. It confirms safety in selected patients.

Minimally invasive subvastus approach: improving the results of total knee arthroplasty: a prospective, randomized trial

BACKGROUND

Minimally invasive knee arthroplasty seeks to diminish the problems of traditional extensile exposures aiming for more rapid rehabilitation of patients after surgery.

QUESTIONS/PURPOSES

To determine if the subvastus approach results in less perioperative pain and blood loss, shorter hospital stay, and improved function at both early and long-term followup.

METHODS

One hundred patients were enrolled in a prospective, randomized trial. Fifty were operated on using a minimally invasive subvastus approach and the other 50 by a conventional, peripatellar approach. Minimum followup was 3 years. A repeated-measures analysis of variance was used to compare the Knee Society score and range of motion during followup.

RESULTS

The minimally invasive approach resulted in greater perioperative bleeding but no increase in transfusions. No differences were found in postoperative pain between groups nor did hospital stay show any differences. The range of motion on the third day after surgery was greater in the minimally invasive group. No differences were found in surgical time, femoral or tibial component orientation or outliers, or complication rates. Both Knee Society score and range of motion were superior using the minimally invasive subvastus approach during followup out to 36 months.

CONCLUSIONS

The minimally invasive subvastus approach can result in improved long-term Knee Society scores and range of motion of total knee arthroplasty without increased risk of component malalignment, surgical time, or complication rate.

LEVEL OF EVIDENCE

Level I, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

An arthroscopic technique to enhance visualization during total hip arthroplasty

This technical note describes the use of an arthroscope or endoscope to enhance visualization during minimally invasive total hip arthroplasty. The arthroscope/endoscope is used to verify seating of the components and to look for potential impingements, loose bodies, or fractures. This technique was successfully used to identify and address 2 bony or soft tissue impingements as well as a calcar fracture that might otherwise have been missed. Although further study is necessary, we believe that this technique might reduce postoperative complications and improve clinical outcomes of total hip arthroplasty.

No benefit of the two-incision THA over mini-posterior THA: a pilot study of strength and gait

Proponents of the two-incision minimally invasive approach for THA have claimed recovery is dramatically better than after other methods of THA, but this has not been confirmed with any objective data. We designed a prospective randomized trial of the two-incision THA versus the mini-posterior technique to determine whether patients having two-incision THA, when compared with patients having mini-posterior THA, had evidence of less muscle damage as reflected by changes in hip muscle strength after surgery, a less antalgic gait as reflected by changes in the single-leg stance time and walking velocity, and better hip function as reflected by changes in the hip moments during level walking and stair climbing as assessed by comprehensive gait analysis testing. Twenty-one patients, including 13 men and eight women, were prospectively randomized to either the two-incision or the mini-posterior approach and completed preoperative and 6-week postoperative three-dimensional gait analyses and isometric strength testing. We found no evidence that patients who had two-incision THA had less muscle damage, less antalgic gait, or better gait kinematics than patients who had mini-posterior THA. Instead, when there was a difference in strength or gait parameters, it was the patients who had mini-posterior THA who tended to have quicker recovery.

LEVEL OF EVIDENCE

Level II, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Computed tomography for preoperative planning in minimal-invasive total hip arthroplasty: radiation exposure and cost analysis

Computed tomography (CT) was used for preoperative planning of minimal-invasive total hip arthroplasty (THA). 92 patients (50 males, 42 females, mean age 59.5 years) with a mean body-mass-index (BMI) of 26.5 kg/m(2) underwent 64-slice CT to depict the pelvis, the knee and the ankle in three independent acquisitions using combined x-, y-, and z-axis tube current modulation. Arthroplasty planning was performed using 3D-Hip Plan(®) (Symbios, Switzerland) and patient radiation dose exposure was determined. The effects of BMI, gender, and contralateral THA on the effective dose were evaluated by an analysis-of-variance. A process-cost-analysis from the hospital perspective was done. All CT examinations were of sufficient image quality for 3D-THA planning. A mean effective dose of 4.0 mSv (SD 0.9 mSv) modeled by the BMI (p<0.0001) was calculated. The presence of a contralateral THA (9/92 patients; p=0.15) and the difference between males and females were not significant (p=0.08). Personnel involved were the radiologist (4 min), the surgeon (16 min), the radiographer (12 min), and administrative personnel (4 min). A CT operation time of 11 min and direct per-patient costs of 52.80 € were recorded. Preoperative CT for THA was associated with a slight and justifiable increase of radiation exposure in comparison to conventional radiographs and low per-patient costs.

Comparison of navigation accuracy in THA between the mini-anterior and -posterior approaches

BACKGROUND

The accuracy of a CT-based hip navigation might depend on surgical approaches, resulting in varying accuracy of implant alignment.

METHODS

We performed primary cementless total hip arthroplasty (THA) with mini-incision surgery (MIS) to 40 well-matched patients (anterior or posterior approaches, 20 hips each), using navigation with surface registration. We investigated cup alignment using postoperative computed tomography (CT) and compared the navigation accuracy between the two approaches, i.e. the difference between intra-operative and postoperative alignments of the cup.

RESULTS

There was no significant difference between the two approaches. The mean navigation accuracies in abduction and anteversion were 2.0 degrees (SD 1.4 degrees) and 2.7 degrees (SD 1.9 degrees), respectively, in the anterior approach, and 2.4 degrees (SD 2.0 degrees) and 2.0 degrees (SD 1.4 degrees), respectively, in the posterior approach. All cup alignments were within 10 degrees of the target orientation.

CONCLUSIONS

This CT-based navigation for MIS-THA provides navigation accuracy without significant differences between the two approaches and with favourable alignment of the cup.

Minimally invasive total hip arthroplasty: a systematic review

The purpose of this study was to compare the operative outcome between mini and standard incisions in total hip arthroplasty (THA). We identified 12 randomised or quasi-randomised control trials (RCT or qRCT) published between 1996 and 2008. Subgroup and sensitivity analyses were performed to evaluate the differences in results for surgical approach, trial quality, and follow-up duration. Operative time and blood loss were significantly reduced in the mini-incision group for studies with the posterior or posterolateral approach. Concerning postoperative complications, there were no significant differences between the two groups with no significant heterogeneity. No differences were observed between the two groups for Harris hip score and radiographic results except for cup anterversion. Although mini-incision appeared to have similar outcomes compared to standard incision, the follow-up is short-term according to current standards in THA. High-quality studies are required to compare the outcomes of these two procedures.

Current state and future of joint replacements in the hip and knee

Joint replacements of the hip and knee are among the most clinically successful operations. According to figures compiled by the American Academy of Orthopaedic Surgeons, the number of primary total hip replacements performed in the USA was 220,000 in 2003. This was 38% more than in 1996 and this number is expected to rise to 572,000 (plus another 97,000 revisions) by 2030. The number of primary total knee replacements performed in 2003 was approximately 418,000 and is expected to rise exponentially with the increasing numbers of baby boomers and the aging population. Current research focuses not only on extending implant longevity, but also on improving function to meet the increased demands of today's patients, who are likely to be younger and more active than their predecessors two decades ago. Potential advancements in arthroplasty surgery include new, more wear-resistant bearing surfaces, porous metals to enhance osseointegration and replace lost bone stock, a clearer understanding of the biological processes associated with periprosthetic osteolysis, minimally invasive surgery and computer assisted surgery. Long-term studies are needed to establish the efficacy of these new technologies.

A modified two-incision technique for primary total hip arthroplasty

BACKGROUND

Minimally invasive surgery can be technically demanding but minimizes surgical trauma, pain and recovery. Two-incision minimally invasive surgery allows only intermittent visualization and may require fluoroscopy for implant positioning. We describe a modified technique for primary total hip arthroplasty, using two small incisions with a stepwise approach and adequate visualization to reliably and reproducibly perform the surgery without fluoroscopy.

MATERIALS AND METHODS

One hundred and two patients with an average age of 60 years underwent modified two-incision minimally invasive technique for primary THA without fluoroscopy. The M/L taper femoral stem (Zimmer, Warsaw, IN) and Trilogy (Zimmer) hemispherical titanium shell, with a highly cross-linked polyethylene liner, was used. Operative time, blood loss, postoperative hospital stay, radiographic outcomes and complications were recorded.

RESULTS

The mean operating time was 77 min. The mean blood loss was 335 cc. The mean hospital stay was 2.4 days. Mean cup abduction angle was 43.8 degrees. Mean leg length discrepancy was 1.7 mm. Thirteen patients had lateral thigh numbness and two patients had wound complications that resolved without any treatment.

CONCLUSION

A modified two-incision technique without fluoroscopy for primary total hip arthroplasty has the advantage of preserving muscles and tendons, shorter recovery and return to function with minimal complications. Provided that the surgeon has received appropriate training, primary total hip arthroplasty can be performed safely with the modified two-incision technique.