Rapid rehabilitation and recovery with minimally invasive total hip arthroplasty

Patient-reported importance of assistive devices in hip and knee replacement Enhanced Recovery after Surgery (ERAS) pathways

Introduction

This study examines patients’ perceptions of the usefulness of occupational therapy and assistive devices provided, in achieving discharge criteria and assisting with activities of daily living once home, following an Enhanced Recovery After Surgery protocol for total hip and total knee replacement patients.

Methods

Two weeks following discharge, 197 patients who had undergone total hip replacement or total knee replacement were telephoned to ask how useful they found occupational therapy education and advice and the assistive devices provided.

Results

114 patients (58%) answered the call. Over 96% of patients found occupational therapy education and advice useful. Ninety-seven percent of posterior total hip replacement patients were still using the assistive devices 2 weeks following discharge, compared to 90% of anterior total hip replacement patients and 87% of total knee replacement patients. Over 95% of all patients found that assistive devices enhanced their ability to undertake activities of daily living, and were extremely or partly useful in achieving early discharge.

Conclusion

Over 85% of patients who responded perceived the occupational therapist’s advice and education, and assistive devices provided, to be useful in achieving discharge criteria, and in enhancing their ability to undertake activities of daily living once back in a home environment.

Total Joint Arthroplasty in a Stand-alone Ambulatory Surgical Center: Short-term Outcomes

For decades, the average hospital stay following total joint arthroplasty (TJA) has been getting shorter. The historical standard was several weeks of hospitalization, yet improvements in perioperative care have reduced the average length of stay to a few days. Medicare recognizes a 3-day inpatient stay as the standard of care following hip or knee replacement. Yet continued advances in minimally invasive surgical techniques, short-acting general anesthetics, long-acting local anesthetics, and blood loss management have further improved the safety and recovery for TJA procedures. Thus, further reductions in postoperative hospitalization have been implemented around the country, with surgeons reporting successful same-day protocols, as defined by hospitalization discharge on the day of surgery. Although these studies have presented results of same-day TJA in the hospital setting, this study is the first to report on the perioperative adverse events and early outcomes of 51 consecutive TJA procedures performed in a stand-alone ambulatory surgical center (ASC). The ASC offers an ideal setting to perform such procedures in the properly selected patient population, obviating any form of postoperative hospitalization. Although 16 (31.4%) of 51 patients reported minor adverse events in the postanesthesia care unit, specifically nausea and/or pain, early intervention permitted 50 (98.0%) of 51 patients to be discharged home, on average 176 minutes after surgery, with 1 patient discharged to a rehabilitation facility as arranged prior to surgery. There were no major adverse events in the 90-day perioperative period, and although 1 (2.0%) patient was hospitalized for persistent incisional drainage, none required admission for pain. This study examines the strict eligibility criteria and perioperative analgesia protocols that permit successful outpatient TJA. [Orthopedics. 2016; 39(4):223-228.].

Surgical treatments for osteoarthritis

There are two main surgical treatments for osteoarthritis: conservative treatments, where the damaged cartilage is left in place, and radical treatments, where the cartilage is replaced by an artificial endoprosthesis; this latter procedure is termed joint arthroplasty. These treatments are only offered to symptomatic patients. Arthrodesis is yet another surgical intervention in cases of osteoarthritis. It will sacrifice the joint's articular function and is performed on small osteoarthritic joints, such as wrists and ankles, for instance. Osteoarthritis symptoms are usually the consequence of an imbalance between the load applied to a joint and the surface available to support that load. Therefore, conservative treatments will either tend to decrease the load exerted on the joint, such as in a tibial valgus osteotomy for instance, or to improve the articular surface supporting that load. Sometimes, both can be provided at the same time; the peri-acetabular osteotomy for hip dysplasia is an example of such a procedure. Conservative treatments are usually offered to young patients in order to delay, if not avoid, the need for a joint prosthesis. They are usually performed before osteoarthritis appears or at an early stage. Joint arthroplasties have overwhelmingly excellent functional results and today's research is directed towards providing rapid recovery, very long-term stability, and the assurance of a good functionality in extreme conditions. However, complications with joint arthroplasties can be serious with little, if any, reasonable salvage solution. Therefore, these procedures are offered to patients who have failed adequate medical treatment measures.

Engineered protein coatings to improve the osseointegration of dental and orthopaedic implants

Here we present the design of an engineered, elastin-like protein (ELP) that is chemically modified to enable stable coatings on the surfaces of titanium-based dental and orthopaedic implants by novel photocrosslinking and solution processing steps. The ELP includes an extended RGD sequence to confer bio-signaling and an elastin-like sequence for mechanical stability. ELP thin films were fabricated on cp-Ti and Ti6Al4V surfaces using scalable spin and dip coating processes with photoactive covalent crosslinking through a carbene insertion mechanism. The coatings withstood procedures mimicking dental screw and hip replacement stem implantations, a key metric for clinical translation. They promoted rapid adhesion of MG63 osteoblast-like cells, with over 80% adhesion after 24 h, compared to 38% adhesion on uncoated Ti6Al4V. MG63 cells produced significantly more mineralization on ELP coatings compared to uncoated Ti6Al4V. Human bone marrow mesenchymal stem cells (hMSCs) had an earlier increase in alkaline phosphatase activity, indicating more rapid osteogenic differentiation and mineral deposition on adhesive ELP coatings. Rat tibia and femur in vivo studies demonstrated that cell-adhesive ELP-coated implants increased bone-implant contact area and interfacial strength after one week. These results suggest that ELP coatings withstand surgical implantation and promote rapid osseointegration, enabling earlier implant loading and potentially preventing micromotion that leads to aseptic loosening and premature implant failure.

Posterior Mini-Incision With Primary Total Hip Arthroplasty: A Nine to Ten Year Follow Up Study

The question has been raised as to whether small incision surgery will compromise long term results of total hip arthroplasty. We report nine to ten years' outcome with posterior mini-incision. Radiographs were measured for component position, polyethylene wear, fixation, and osteolysis. Sixty-two of the original 86 patients (76 of 100 hips) were alive and available for study with 17 patients deceased (with known results) and seven (8%) lost to follow-up. The result was rated as excellent in 70 of 75 remaining hips (93%). Eighty-nine of 93 hips (96%) with known results had the original implants. Radiographically, wear was a mean 0.015 ± 0.009 mm/year, and no hip had impending failure. There were four revisions, 2 for dislocation, 1 for fracture, and 1 for loose cup.

Return to work after total hip and knee arthroplasty: results from a clinical study

The aim of this study was to measure return to work and duration until return to work in patients undergoing total hip or knee arthroplasty (THA or TKA). This prospective study included patients under 65 years of age, undergoing THA or TKA, who provided information on their work status preoperatively (paid work yes/no and working hours) and 1 year thereafter (paid work yes/no, working hours and time until return to work). Seventy-one THA and 64 TKA patients had a paid job preoperatively. The employment rates 1 year postoperatively were 64/71 (90 %) after THA and 53/64 (83 %) after TKA. Of those who returned to work, 9/64 (14 %) of THA patients and 10/53 (19 %) of TKA patients worked less hours than preoperatively [mean decrease of 16 (SD 11.5) and 14 (SD 13.0) hours, respectively]. The mean time to return to work was 12.5 (SD 7.6) and 12.9 (SD 8.0) weeks in THA and TKA, respectively. The majority of working patients who underwent THA or TKA returned to work, after approximately 12 weeks. A considerable proportion of the patients returning to work worked less hours than preoperatively. More research into patients who do not return or decrease their working hours is needed.

Agreements and disagreements in exercise therapy prescriptions after hip replacement among rehabilitation professionals: a multicenter survey

Background

Exercise therapy following total hip replacement (THR) is considered to be important during the initial postoperative care, but till date only a few evidence-based recommendations exist. The aim of this survey was to identify prescription standards among different rehabilitation professionals, for the exercise therapy management after THR in Germany.

Methods

The study was a cross-sectional survey. Standardized questionnaires were sent to 38 eligible rehabilitation facilities in Germany. Participating surgeons, orthopaedic physicians, physiotherapists and exercise therapists rated the optimal early weight-bearing, resistance training, key components and dose of exercise therapy, and the hip loading during exercising. The returned questionnaires were then analyzed for level of agreement (≥80 %) among respondents.

Results

313 rehabilitation professionals from 28 clinics returned completed questionnaires and were considered eligible for analysis. Out of total respondents, 53.9 % (cemented THR) and 18.2 % (uncemented THR) recommended full weight-bearing within five days after surgery. Commencement of resistance training later than three weeks after surgery is recommended by 20.6 % (36 %) for cemented (uncemented) prosthesis. Feedback varied significantly amongst the professions. Regarding the overall objectives of rehabilitation after hip replacement, respondents agree in six out of eight requested items. Agreement concerning priorities of specific exercises was achieved in three out of twelve items. The recommended exercise therapy dose varied significantly with working experience (p = 0.02).

Conclusion

Rehabilitation professionals mainly disagreed with the exercise therapy prescriptions following the total hip replacement during the initial postoperative care in Germany.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-015-0646-7) contains supplementary material, which is available to authorized users.

The Impact of Study Period on Perioperative Outcomes Following Hip Arthroplasty

We hypothesized that the time period studied would have a greater impact on perioperative outcomes than the hip arthroplasty procedure performed, demonstrating concerns with studies comparing new techniques to "historical" controls. One hundred total hip arthroplasty (THA) and 100 surface replacement arthroplasty (SRA) patients performed between 2004 and 2010 ("historical" period) were matched and compared to 50 THA and 50 SRA patients performed between 2010 and 2012 ("recent" period). Time to discharge was significantly improved for both the THA and SRA groups in the recent versus historical period by 16hours (P<0.001). At both periods, THA patients were discharged earlier by 9hours versus SRAs (P<0.0001). Study time frame had a greater impact than the operative procedure on perioperative metrics.

HIP osteoarthritis and work

Epidemiological evidence points strongly to a hazard of hip osteoarthritis from heavy manual work. Harmful exposures may be reduced by the elimination or redesign of processes and the use of mechanical aids. Reducing obesity might help to protect workers whose need to perform heavy lifting cannot be eliminated. Particularly high relative risks have been reported in farmers, and hip osteoarthritis is a prescribed occupational disease in the UK for long-term employees in agriculture. Even where it is not attributable to employment, hip osteoarthritis impacts importantly on the capacity to work. Factors that may influence work participation include the severity of disease, the physical demands of the job, age and the size of the employer. Published research does not provide a strong guide to the timing of return to work following hip arthroplasty for osteoarthritis, and it is unclear whether patients should avoid heavy manual tasks in their future employment.

Two-Day Length of Stay is Not Inferior to 3 Days in Total Knee Arthroplasty with Regards to 30-Day Readmissions

The impact of a shortened length of stay (LOS) following total knee arthroplasty (TKA) on the risk of readmission is not well documented despite recent trends towards shorter hospitalization. We retrospectively compared the adjusted risk of 30-day readmission following TKA between patients with 2-, 3- and 4-day LOS using current postoperative care protocols. A total of 23,655 consecutive primary, unilateral TKAs operated between 01/01/2009 and 12/31/2011 were studied retrospectively using non-inferiority testing. The main outcome was 30-day readmission. Two-day LOS decreased the odds of readmission by a factor of 0.96, with an upper bound one-sided 95% confidence interval of 1.10. After adjusting for other variables, LOS of 2 days is not inferior to 3 days with respect to the risk of 30-day readmission.

The Effect of Disease Severity and Comorbidity on Length of Stay for Orthopedic Surgery in Rheumatoid Arthritis: Results from 2 UK Inception Cohorts, 1986-2012

OBJECTIVE

To examine factors predicting length of stay (LoS) for orthopedic intervention in rheumatoid arthritis (RA).

METHODS

LoS for orthopedic intervention was examined in 2 consecutive, multicenter inception cohorts: the Early RA Study (n = 1465, 9 centers) and the Early RA Network (n = 1236, 23 centers). Date, type of orthopedic procedure, and LoS were recorded and validated against national data, the UK National Joint Registry, and the UK Hospital Episode Statistics database. Clinical, laboratory, and radiographic measures and comorbidity recorded at baseline and annually were examined for their predictive power on LoS using regression analysis.

RESULTS

A total of 770 of 2701 patients (28.5%) had 1602 orthopedic interventions: 40% major (mainly total hip/knee replacements), 24% intermediate (mainly hand/wrist and ankle/foot surgery), and 16% minor (mainly soft tissue surgery). Median (interquartile range) LoS was 8 (5-13), 3 (1-5), and 1 (0-2) days for major, intermediate, and minor interventions, respectively. Older age predicted longer LoS (p < 0.001) whereas a more recent operation year predicted shorter LoS (p < 0.001). Markers of active disease, namely low hemoglobin, high Health Assessment Questionnaire, and high Disease Activity Scores in the first year all predicted longer LoS for all types of surgery (p = 0.001, p < 0.001, p = 0.05, respectively). Presence of 1 or more major comorbidities predicted longer LoS (p < 0.001).

CONCLUSION

Comorbidity and standard clinical and laboratory markers of disease activity affect the LoS for orthopedic surgery in RA, which has important clinical and economic implications, providing a target for improving patient outcomes.

A mini-anterior approach to the hip for total joint replacement: optimising results

Direct anterior approaches to the hip have gained popularity as a minimally invasive method when performing primary total hip replacement (THR). A retrospective review of a single institution joint registry was performed in order to compare patient outcomes after THR using the Anterior Supine Intermuscular (ASI) approach versus a more conventional direct lateral approach. An electronic database identified 1511 patients treated with 1690 primary THRs between January 2006 and December 2010. Our results represent a summary of findings from our previously published work. We found that patients that underwent an ASI approach had faster functional recovery and higher Harris hip scores in the early post-operative period when compared with patients who had a direct lateral approach The overall complication rate in our ASI group was relatively low (1.7%) compared with other series using the same approach. The most frequent complication was early periprosthetic femoral fractures (0.9%). The dislocation rate in our series was 0.4% and the prosthetic joint infection rate was 0.1%. We suggest that the ASI approach is acceptable and safe when performing THR and encourages early functional recovery of our patients.

Cite this article: Bone Joint J 2014;96- B(11 Suppl A):32–5.

[Complications after minimally invasive total hip arthroplasty]

BACKGROUND

The goal of minimally invasive surgery in total hip arthroplasty (MIS-THA) is reduction of surgical trauma without any limitations regarding exposure of the femur and acetabulum to achieve reproducible results. Despite improved instrumentation the implementation of these techniques is associated with a risk of higher complication rates.

AIM

The article describes specific and unspecific complications of MIS-THA and gives hints and tips on how to avoid them.

MATERIAL AND METHODS

In a retrospective study 152 THA revisions following MIS-THA were examined and an error analysis was performed.

RESULTS

The study of 152 MIS-THA revisions included 87 female and 65 male patients. A gender-specific incidence of complications could not be found. The most common indication for revision surgery was due to recurrent dislocation. An increased incidence of fractures of the greater trochanter was observed using the anterolateral approach with the patient in a supine position.

DISCUSSION

The MIS-THA procedure contributes to excellent early rehabilitation when performed correctly. The muscle preserving aspect can be counted as an advantage particularly for young patients. This patient collective has a high risk to undergo revision surgery.

A systematic review and meta-analysis of the standard versus mini-incision posterior approach to total hip arthroplasty

The mini-incision posterior approach may appeal to surgeons comfortable with the standard posterior approach to the hip. We present the first systematic review and meta-analysis of these two approaches. Twelve randomised controlled trials and four non-randomised trials comprising of 1498 total hip arthroplasties were included. The mini-incision posterior approach was associated with an early improvement in Harris hip score of 1.8 points (P<0.001), reduced operating time (5minutes, P<0.001), length of hospital stay (14hours, P<0.001), intraoperative and total blood loss (63ml, P<0.001 and 119ml, P<0.001 respectively). There were no statistically significant differences in the incidence of dislocation, nerve injury, infection or venous thromboembolic events. The minimally invasive posterior approach appears to provide a safe and acceptable alternative to the standard incision posterior approach.

Outpatient surgery as a means of cost reduction in total hip arthroplasty: a case-control study

BACKGROUND

The current healthcare market coupled with expedited recovery and improvements in analgesia have led to the development of total hip arthroplasty being performed as an outpatient procedure in selected patients.

QUESTIONS/PURPOSES

The purpose of this study is to compare outcomes and cost-effectiveness of traditional inpatient THA with outpatient hip replacement at the same facility.

PATIENTS AND METHODS

This observational, case-control study was conducted from 2008 to 2011. One hundred nineteen patients underwent outpatient THA through a direct anterior approach. These cases were all performed by a single surgeon. Outpatient cases were then compared to inpatient hospital controls performed by the same surgeon at the inpatient hospital facility.

RESULTS

Complications, length of stay, demographic data, and overall costs were compared between groups. There was no difference in complications or estimated blood loss between groups. Most notably, the average overall cost in the outpatient setting was significantly lower than inpatient, $24,529 versus $31,327 (p = 0.0001).

CONCLUSIONS

This study demonstrates that appropriately selected patients can undergo THA in an outpatient setting with no increase in complications and at a substantial savings to the healthcare system.

Total hip arthroplasty through the mini-incision (Micro-hip) approach versus the standard transgluteal (Bauer) approach: a prospective, randomised study

PURPOSE

To compare outcome after total hip arthroplasty (THA) through the mini-incision approach versus the standard transgluteal approach.

METHODS

80 women and 63 men aged 33 to 89 (mean, 62) years with primary osteoarthritis of the hip were randomised to undergo unilateral THA through a mini-incision approach (Micro-hip, n=55) or standard, lateral, transgluteal approach (Bauer, n=88). Levels of haemoglobin, haematocrit, serum creatine kinase, and C-reactive protein, length of hospital stay, mobilisation, and any complication were recorded. Visual analogue scale (VAS) for pain was assessed. Hip function was assessed using the Harris Hip Score and the Oxford Hip Score, whereas general health was assessed using the EQ-5D general health questionnaire. The cup inclination and varus/valgus of the stem position were measured using a goniometer.

RESULTS

The Micro-hip group achieved a significantly lower mean incision length (9.3 vs. 13.4 cm, p<0.001), mean surgical time (60 vs. 68 minutes, p=0.021), mean reduction in haemoglobin level (2.1 vs. 2.8 g/dl, p<0.001), and mean VAS for pain from hour 6 to day 6 (all p<0.05). One patient in the Micro-hip group developed early aseptic loosening of the cup and underwent revision surgery at month 4. Three patients in the Bauer group and one patient in the Micro-hip group sustained intra-operative nondisplaced fractures of the proximal femur, which were fixed with cerclages. Two patients in the Microhip group developed deep vein thrombosis during week 1.

CONCLUSION

THA through the Micro-hip approach achieved faster pain relief.

Treatment of femoral neck fracture with a minimal invasive surgical approach for hemiarthroplasty - clinical and radiological results in 180 geriatric patients

Purpose :

The Direct Anterior Approach (DAA) is well established as a minimal access approach in elective orthopaedic hip surgery. For the growing number of elderly patients with femoral neck fractures treated with Bipolar Hip Hemiarthroplasty (BHH), only a few results do exist. The study shows the clinical and radiological outcome for 180 patients treated by a modified DAA with BHH.

Materials and Methods :

The data of 180 geriatric patients with medial femoral neck fractures were evaluated retrospectively. The general and surgical complications, mobilisation using the Timed Up and Go test (TUG), the social environment pre- and postoperative and the radiological results have been compared with established approaches for geriatric hip surgery.

Results :

After joint replacement, 18 (10%) patients were developed pneumonia, of which 3 (1.7%) died during hospitalisation. In 7 cases (4%), surgical revision had to be carried out: three times (1.7%) because of a seroma, three times (1.7%) because of subcutaneous infection, and one time (0.6%) because the BHH was removed, owing to deep wound infection. One dislocation (0.6%) occurred, as well as one femoral nerve lesion (0.6%) occured. 88.3% of patients were mobilised on walkers or crutches; the Timed Up and Go Test showed a significant improvement during inpatient rehabilitation. 83% were discharged to their usual social environment, 10% were transferred to a short-term care facility and 7% were relocated permanently to a nursing home. 3/4 of patients had a cemented stem alignment in the range between -5° and 5°, while 2/3 of patients had a maximum difference of 1 cm in leg length.

Conclusion :

Using the modified DAA, a high patient satisfaction is achieved after implantation of a BHH. The rate of major complications is just as low as in conventional approaches, and rapid mobilisation is possible.

Assessment of the Size of the Surgical Site in Minimally Invasive Hip Surgery

Objective: Minimally invasive approaches to the hip are beneficial to the patient, but reduce the space available for manipulation by the surgeon. Determining the available working space is important for the development of surgical instruments, to track movements during surgery, as well as to classify the invasiveness of the procedure. Approach: We evaluate three measurement methods to assess the volume of eight surgical sites in a cadaver study. The cavities were filled with an alginate cast to determine its dimensions. Second, the depth, height, and width of the surgical site were measured with a ruler and the volume was calculated. Last, the surface registration method was used to reconstruct the site. Results: We found that the mold filling method provides accurate results in determining the volume of a surgical site. The manual method using a ruler showed excellent reliability, but the calculations tended to overestimate the volume of the surgical site. In contrast, surface reconstruction tended to underestimate the volume of a surgical site, but the results closer resembled the ones derived from the mold filling method. Innovation: We presented a new method to assess the size of the surgical site intraoperatively in minimally invasive hip surgery. Conclusion: The manual method is reliable, but not as accurate as the surface reconstruction, while the mold filling method cannot be used in an intraoperative setup. Although surface reconstruction showed deficits regarding reliability, due to the lack of direct contact to the patient, it remains an appealing technique to measure the surgical site.

Comparison of the Outcome in Bilateral Staged Total Hip Arthroplasty: Modified Two-Incision Minimally Invasive Technique versus the Conventional Posterolateral Approach

This retrospective study was undertaken to compare the outcomes of staged bilateral total hip arthroplasty (THA) by the conventional approach with those of two-incision minimally invasive (MIS-2) THA in terms of clinical and radiological results, complications, and patient preferences. Twenty-two patients aged 30 to 80 years underwent staged bilateral THA. The conventional posterolateral approach was used on the first hips treated and a modified MIS-2 approach on the second hips. The mean time between the first and second procedures was 73.8 months, and the patients were followed up for at least 12 months after both procedures. At the last follow-up visits, THA via the MIS-2 approach was found to provide significantly earlier partial-weight-bearing ambulation, better postoperative Harris hip scores, and better ability to sit cross-legged and was found to be more preferred by patients than conventional THA. There were no significant differences in the complication rates for the two approaches. The present results show that MIS-2 THA is as safe as the conventional posterolateral approach in experienced hands and presents no additional complication risks.

Modular versus nonmodular neck femoral implants in primary total hip arthroplasty: which is better?

BACKGROUND

Restoration of the hip center is considered important for a successful THA and requires achieving the right combination of offset, anteversion, and limb length. Modular femoral neck designs were introduced to make achieving this combination easier. No previous studies have compared these designs in primary THA, and there is increasing concern that modular designs may have a higher complication rate than their nonmodular counterparts.

QUESTIONS/PURPOSES

We therefore asked (1) whether use of a stem with a modular neck would restore limb length and offset more accurately than a stem with a nonmodular neck, and (2) whether patients who received modular neck systems had better hip scores or a lower frequency of complications and reoperations than those receiving a comparable nonmodular stem.

METHODS

Two cohorts of patients undergoing primary THAs, 284 patients with a nonmodular neck and 594 patients with a modular neck, were treated by one surgeon through a posterior approach. These were two nearly sequential series with little overlap. Harris hip scores and SF-12 outcomes surveys were administered at followup with a mean of 2.4 years (maximum, 5.9 years).

RESULTS

In the modular neck cohort, a greater proportion of patients had equal (within 5 mm) radiographic limb lengths (89%, compared with 77% in nonmodular cohort p = 0.036), and a smaller offset difference (6.1 versus 7.5 mm, p = 0.047) was observed. Whether these statistical differences are clinically important is unclear. A smaller proportion of patients in the modular neck cohort achieved equal apparent or clinical limb length at 1 year (85% versus 95%, p < 0.001) and at 2 years (81% versus 94%, p < 0.001). In addition, these differences did not appear to result in better Harris hip or SF-12 scores, fewer complications, or reduced likelihood of revision surgery.

CONCLUSIONS

Use of modular neck stems did not improve hip scores nor reduce the likelihood of complications or reoperations. Because of their reported higher risks, there is no clear indication for modularity with a primary THA, unless the hip center cannot be achieved with a nonmodular stem, which is rare.

LEVEL OF EVIDENCE

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

Does the direct anterior approach in THA offer faster rehabilitation and comparable safety to the posterior approach?

BACKGROUND

Newer surgical approaches to THA, such as the direct anterior approach, may influence a patient's time to recovery, but it is important to make sure that these approaches do not compromise reconstructive safety or accuracy.

QUESTIONS/PURPOSES

We compared the direct anterior approach and conventional posterior approach in terms of (1) recovery of hip function after primary THA, (2) general health outcomes, (3) operative time and surgical complications, and (4) accuracy of component placement.

METHODS

In this prospective, comparative, nonrandomized study of 120 patients (60 direct anterior THA, 60 posterior THAs), we assessed functional recovery using the VAS pain score, timed up and go (TUG) test, motor component of the Functional Independence Measure™ (M-FIM™), UCLA activity score, Harris hip score, and patient-maintained subjective milestone diary and general health outcome using SF-12 scores. Operative time, complications, and component placement were also compared.

RESULTS

Functional recovery was faster in patients with the direct anterior approach on the basis of TUG and M-FIM™ up to 2 weeks; no differences were found in terms of the other metrics we used, and no differences were observed between groups beyond 6 weeks. General health outcomes, operative time, and complications were similar between groups. No clinically important differences were observed in terms of implant alignment.

CONCLUSIONS

We observed very modest functional advantages early in recovery after direct anterior THA compared to posterior-approach THA. Randomized trials are needed to validate these findings, and these findings may not generalize well to lower-volume practice settings or to surgeons earlier in the learning curve of direct anterior THA.

Medical Aspects of Fitness to Drive

Orthopedic surgeons and other stakeholders need better return-to-driving guidelines for post–orthopedic surgery and trauma patients. The state of the current orthopedic research is in need of better methodology, particularly regarding control over the cognitive domain’s influence on the physical domain. Recommendations need to be based on an individual’s assessment of physical performance rather than the passage of time after surgery. This article highlights the areas of concern for driving research in the orthopedic community and how they can affect study design.

Force transmission in offset broach handles used for hip replacement: comparison of three different designs

In minimally invasive hip arthroplasty double offset broach handles are used, to facilitate the preparation of the femoral canal. The aim of this study was to quantify the differences in force and impulse transmission between two double offset broach handles and a single offset broach handle. Two double offset broach handles (A European version, B American version) were compared to a single offset broach handle. A surgical hammer was used to give a variable impact to the head of the broach handle. Thirty measurements for each of five falling heights were recorded for each broach handle. The force measured by a load cell connected to the broaches was used to obtain the maximum force peak and to calculate the impaction impulse. Normal data distribution was assumed and analysis of variances was performed. Results have demonstrated that the highest values of the force peak and force impulse were found in the single offset broach handle. Broach handle A had higher impulse values and lower maximum force values compared to broach handle B. The lateral lever arm has a measurable effect on the force transmission. In double offset broach handles less energy is transmitted to the tip. Surgeons have to be aware of the differences between the broach handles when using them intraoperatively.

Multimodal analgesia therapy reduces length of hospitalization in patients undergoing fusions of the ankle and hindfoot

BACKGROUND

Multimodal postoperative analgesia employs multiple medications given perioperatively to block the generation and perception of pain at different points in the nociceptive pathway. This retrospective study examines its effect on the length of stay for patients undergoing hindfoot and ankle fusions.

METHODS

All patients operated upon by the senior authors between 2007 and 2011, inclusive, underwent ankle fusion, subtalar fusion, pantalar arthrodesis, triple arthrodesis, or combined ankle/subtalar fusions. The perioperative pain management was either the "traditional" method (patient-controlled-analgesia-delivered parenteral narcotics beginning immediately postoperatively) or the multimodal pain protocol (pre- and postoperative oral administration of opioids, celecoxib, pregabalin, acetaminophen, and prednisone). The choice of pain protocol was up to the surgeons, without any exclusion criteria. Physical therapy protocols were not changed during the study. The study included 220 patients; 175 received the multimodal protocol and 45 received traditional management. Multimodal protocol patients were younger (53.9 vs 59.7 years; P < .003), but there were no other differences between the groups with respect to gender, obesity, body mass index, tobacco use, alcohol use, or comorbidities. Complex cases (revision surgeries, Charcot joint surgeries, multiple concurrent procedures, etc) were equally represented in both groups.

RESULTS

Multimodal protocol patients had lower lengths of stay (2.5 days; 95% confidence interval [CI], 1.4-3.7) than traditional pain management patients (4.2 days; 95% CI, 2.7-5.7; P < .001). This was also true for both complicated and uncomplicated surgeries when considered separately.

CONCLUSION

This study provides the first evidence that multimodal therapy reduces the length of stay for patients undergoing major hindfoot or ankle fusion surgery, regardless of surgical complexity.

LEVEL OF EVIDENCE

Level III, comparative series.

Modified direct anterior approach in minimally invasive hip hemiarthroplasty in a geriatric population: a feasibility study and description of the technique

INTRODUCTION

The direct anterior approach (DAA) is generally accepted method for minimal invasive arthroplasty of the hip. As good results for total hip arthroplasty are already published, there is a lack of evidence for the implantation of bipolar hip hemiarthroplasty (BHH) in elderly patients with osteoporosis after femoral neck fracture.

MATERIALS AND METHODS

For hip arthroplasty using a direct anterior approach (DAA) in elderly patients with femoral neck fractures, a number of modifications of the original technique are being described. The modified DAA considers in particular the co-morbidity and the bone quality of the geriatric patient population. A consecutive series of 16 hemiarthroplasties using this technique is presented. In all 16 cases, the BHH was implanted in modified DAA technique. Mobility measured by 4-item Barthel Index, pain via visual analogue scale (VAS), duration of surgery, external length of incision and blood loss were evaluated.

RESULTS

There was no major operative complication during the procedures. The pain level decreased from 7 (preoperatively) to 0 at postoperative day 40. The Barthel Index increased from 5 at first postoperative day to 40 at day 40. Early postoperative mobilisation is efficiently accelerated. Mean operating time was 71 min; the medium skin incision length was 8 cm. The mean haemoglobin level decreased from 118 g/dl preoperatively to 101 g/dl at first postoperative day.

CONCLUSION

The described modifications of the DAA help to implant a BHH gently in elderly patients with increasing risk of complications like iatrogenic fractures, wound or prosthesis infections and haematoma. This will hopefully lead to a faster rehabilitation and lower mortality rate for patients with femoral neck fractures in the future.

Prospective randomized study of direct anterior vs postero-lateral approach for total hip arthroplasty

Benefits of a direct anterior approach (DAA) versus a posterior-lateral (PA) approach to THA were assessed in a single-surgeon, IRB-approved, prospective, randomized clinical study. Subjects (43 DAA and 44 PA) were evaluated at 6 weeks, and 3, 6 and 12 months. The primary end point was ability to climb stairs normally and walk unlimited at each time point. Secondary end points included assessment by several outcome instruments. DAA subjects performed better during the immediate post-operative period; they had lower VAS pain scores on the first post-operative day, more subjects climbing stairs normally and walking unlimited at 6 weeks, and higher HOOS Symptoms scores at 3 months. There were no significant differences between groups at later time points. Findings confirm previous reports of benefits of DAA versus PA in early post-operative phases.

Does hip implant positioning affect the peak external adduction moments of the healthy knees of subjects with total hip replacements?

After unilateral total hip replacement (THR) for hip osteoarthritis (OA), knee OA incidence or progression is common. The contralateral knee is at particular risk, and some have speculated that abnormal THR-hip biomechanics contributes to this asymmetry. We investigated the relationships between operated-hip joint geometry or gait variables and the peak external knee adduction moments-an indicator of knee OA risk-in 21 subjects with unilateral THRs. We found that the peak adduction moment was 14% higher on the contralateral versus the ipsilateral knee (p = 0.131). The best predictors of ipsilateral knee adduction moments were superior-inferior joint center position and operated-hip peak adduction moment (adj R(2)  = 0.291, p = 0.017). The sole predictor of the contralateral knee adduction moment was the medial-lateral hip center position (adj R(2)  = 0.266, p = 0.010). A postoperative medial shift of the hip center was significantly correlated with a lower postoperative contralateral/ipsilateral knee adduction moment ratio (R = 0.462, p = 0.035). Based on these relationships, we concluded that implant positioning could influence the biomechanical risk of knee OA progression after THR. Although implant positioning decisions are necessarily driven by other factors, it may be appropriate to assess individual THR candidate's knee OA risk and adjust perioperative management accordingly.

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 minimally invasive approach for total hip arthroplasty does not diminish early post-operative outcome in obese patients: a prospective, randomised trial

PURPOSE

The benefits of minimally invasive surgical techniques in total hip arthroplasty (THA) are well known, but concerns about applying those techniques in obese patients are controversial. We prospectively compared patients with increased body mass index (BMI ≥ 30) undergoing THA with normal weight patients.

METHODS

A total of 134 patients admitted for unilateral THA were randomised to have surgery through either a transgluteal or a minimally invasive approach (MicroHip). In each group a BMI ≥ 30 was used to define obese patients. Pre- and early post-operative demographics, intraoperative data, baseline haematological values, hip function (Harris Hip Score, Oxford Hip Score) and quality of life (EQ-5D) were assessed with follow-up at three months.

RESULTS

Duration of surgery, blood loss, C-reactive protein levels, radiographic measurements and complication rates were comparable in all groups. There was a tendency for lower serum creatine kinase levels in the MicroHip group. Intraoperative fluoroscopic time and dose area products were significantly elevated in patients with a BMI exceeding 30 regardless of the approach used. Time points of mobilisation, length of hospital stay and functional outcome measurements were similar in the different weight groups.

CONCLUSIONS

Our data suggest that obese patients gain similar benefit from MicroHip THA as do non-obese patients. The results of this study should be further investigated to assess long-term survivorship.

The difference between stretching and splitting muscle trauma during THA seems not to play a dominant role in influencing periprosthetic BMD changes

BACKGROUND

Periprosthetic bone adaptation in the proximal femur after total hip arthroplasty can result in reduced bone mineral density that may contribute to increased risk of aseptic loosening or fracture. Functional loading of the proximal femur postoperatively may depend upon the type of surgical muscle trauma - splitting or stretching - and is likely to influence the preservation of periprosthetic bone mineral. Since the maintenance of bone is known to be highly age and gender dependent, the aim of this study was to investigate the interplay between muscle trauma and age and gender influences on periprosthetic bone adaptation.

METHODS

Ninet y-three patients were consecutively recruited into either a transgluteal (splitting) or anterolateral (stretching) surgical approach and examined 7 days and 12 months after an elective primary hip arthroplasty (Zweymüller Alloclassic stem), using dual-energy X-ray absorptiometry measurements to quantify proximal femoral bone mineral density.

FINDINGS

The results indicate that neither gender, age nor surgical trauma type, but only the combination of age and gender, were significant predictors of postoperative remodelling rate, with younger men (<65) and older women exhibiting the largest bone atrophy.

INTERPRETATION

This study has demonstrated that the difference between stretching and splitting surgical trauma to the muscles during total hip replacement does not play a dominant role in influencing periprosthetic bone mineral changes. However, this data does suggest that certain patient populations may particularly benefit from muscle and bone preserving procedures.

Two-incision minimally invasive vs standard total hip arthroplasty: comparison of component position and hospital costs

Forty-nine patients undergoing 2-incision total hip arthroplasty were matched by age, gender, body mass index, and comorbidity to patients undergoing a standard lateral Hardinge approach. Hospital costs and charges were compared along with length of stay, component position, and complication rates. Component position and complication rates were identical for the 2 groups. However, hospital costs and charges were significantly lower for the 2-incision group, as was length of stay.

The optimal skin incision for minimally invasive total hip arthroplasty performed via the anterolateral approach

Twelve total hip arthroplasty procedures were performed in fresh cadaveric specimens via the anterolateral approach using straight 9-cm incisions placed in 2 different locations with respect to anatomical landmarks. During each procedure, the forces applied to the wound edges by each of the hip instruments and the pressures and strains generated along the wound edges were measured. Pressures ranging from 40 to 190 kPa were developed between the retractors and the wound edges during acetabular reaming and femoral rasping. The resulting strain along the wound edges averaged 28% during acetabular reaming and 34% during femoral broaching (P < .0001). Maximum strains were recorded at the ends of each incision and averaged 58% and 61%, respectively (P < .0001). These results were independent of the anatomical placement of the skin incision. In total hip arthroplasty, the mechanical trauma associated with the procedure is primarily determined by the surgical approach to the hip and the properties of the subcutaneous tissues, and not the anatomical location of the skin incision itself.

[Minimally invasive posterior approach for total hip arthroplasty]

The mini-posterior approach for total hip arthroplasty (THA) belongs to the mini-incision approaches. In comparison to standard approaches, less muscle trauma resulting in less pain, less blood loss and faster rehabilitation in the early postoperative period are attributed to this approach, as known for all other minimally invasive approaches. In a prospective study of 100 cases of THA it could be shown that this is true when comparing the mini-posterior approach with the posterolateral approach. Lower levels of muscle enzymes as a parameter for muscle trauma, could not be seen.

Functional recovery, complications and CT positioning of total hip replacement performed through a Röttinger anterolateral mini-incision. Review of a continuous series of 103 cases

INTRODUCTION

Minimally invasive approaches entail an increased risk of malpositioning and peri-operative complications. Most studies analyzed these data only on plain X-ray rather than computed tomodensitometry (CT) in assessing implant positioning.

HYPOTHESIS

A Röttinger minimally invasive anterolateral (MIS-AL) approach provides rapid complication-free functional recovery with reliable implant positioning on CT-scan.

PATIENTS AND METHOD

One hundred and three primary cemented total hip replacements (THR) performed by a single surgeon using a MIS-AL approach underwent clinical assessment at six weeks and three, six and 12 months on X-ray, including CT and postoperative myoglobinemia and creatine phosphokinase (CPK).

RESULTS

Pain, on a visual analog scale, was graded less than 1 at 36 hours; canes ceased to be used at a mean three weeks; and mean Postel-Merle-D'Aubigné score at six months was 17.36 (range, 13-18). There were ten approach-related complications (9.7%: one femoral perforation, two dislocations, two femoral neck fissures, two cases of meralgia paresthetica and three of tensor tendinitis). Mean CPK level was 390.9 ± 252μg/L (range, 88-1095μg/L) at 24 hr postoperatively and 319 ± 256μg/L (95-1028 μg/L) at 48 hr. Mean postoperative myoglobinemia was 299 ± 152.6μg/L (75-914μg/L). Mean acetabular inclination and anteversion on CT were respectively 44.7° ± 4.6° (34° - 56°) and 9.2°±9.2° (-17°-35°) and mean femoral anteversion 23.5° ± 9.4° (2°-53°).

DISCUSSION

Functional recovery was quick, but with an 8.7% complications rate (excluding four cases of spontaneously resolved tendon pain). CT showed reliable cup positioning, but a wide scatter in femoral anteversion. Elevated muscle enzyme levels possibly testified to approach-related tissue attrition. The MIS-AL approach involves a learning curve to avoid femoral perforation. It provided rapid functional recovery with reliable positioning, at least for the cup, and a low rate of associated complications.

LEVEL OF EVIDENCE

III, prospective continuous study.

Rehospitalizations, early revisions, infections, and hospital resource use in the first year after hip and knee arthroplasties

We examined 3 negative outcomes for 58 351 hip and knee arthroplasty patients: rehospitalization, revision and infection, and their impact on resource use in the year after surgery. In the year before surgery, 12.9% of elective hip and 10.2% of knee patients were hospitalized. In the year after, 14.8% of elective hip and 15.5% of knee patients were hospitalized, representing a 15% and 52% increase, respectively. Twenty-eight percent of emergent hip patients were hospitalized at least once preoperatively; this did not change after surgery. Revision occurred in 2.0% of emergent hip, 1.7% of elective hip, and 0.9% of knee patients. Joint infection was diagnosed in 1.3% of patients. The increased hospitalization after the elective hip and knee procedures represents an incremental cost of 10% over the index hospital stay.

Contralateral hip and knee gait biomechanics are unchanged by total hip replacement for unilateral hip osteoarthritis

Both the hip and knee contralateral to a total hip replacement (THR) have an increased risk of osteoarthritis (OA) progression, and ultimate joint replacement. It is also known that abnormal gait contributes to OA progression. For these reasons, we conducted a longitudinal analysis of contralateral hip and knee gait during the first year after unilateral THR to determine whether abnormal contralateral gait biomechanics emerge after THR. We analyzed the sagittal plane dynamic range of motion and 3D peak external moments from the asymptomatic hip and knee contralateral to a THR in a group of 26 subjects, evaluated preoperatively, and 3, 12, 24, and 52 weeks after THR, and a group of control subjects. We used t-tests and repeated measures ANOVA to test the hypotheses that contralateral hip and knee gait parameters are normal preoperatively, but change after THR. Preoperatively, the contralateral hip abduction moment and the contralateral knee adduction, flexion, and external rotation moments were significantly higher than normal in the THR group (p ≤ 0.048). Apart from the peak hip extension moment, which decreased three weeks after surgery but returned to its preoperative value thereafter, there were no longitudinal changes during the study period (p ≥ 0.141). Preoperative gait abnormalities persisted postoperatively. Notably, the contralateral knee adduction moment was 32% higher than normal in the THR group. These results indicate a biomechanical basis for the increased contralateral OA risk after unilateral THR, and suggest that some patients may benefit from strategies to reduce loading on the contralateral limb.

Hip replacement in the very elderly: selecting a suitable candidate

The selection of a suitable candidate for hip arthroplasty involves several important patient-specific considerations. Advanced age may be considered a relative contraindication for elective surgery, and may unfortunately cause a stereotypical dismissal of very elderly patients with a painful hip. However, several studies have demonstrated the exceptional safety and symptomatic benefits of hip arthroplasty in octogenarians and nonagenarians when appropriate medical precautions and preparations are utilized. The very elderly present specific social and medical scenarios that must be identified to establish an accurate risk assessment and achieve an optimal postoperative result. Although a greater likelihood of perioperative complications exists, the very elderly can expect to achieve highly significant pain relief and functional improvement after hip replacement. Future studies will focus on improvements in outcomes after hip replacement that may be realized with new advances in postoperative protocols.

Total hip arthroplasty using two-incision technique

BACKGROUND

To evaluate the effectiveness of minimally invasive surgery total hip arthroplasty (THA) using the two-incision technique as described by Mears.

METHODS

From January 2003 to December 2006, sixty-four patients underwent total hip arthroplasty using the one-incision (group I) and two-incision (group II) technique by one surgeon. There were 34 hips in group I and 30 hips in group II. There was no difference in age, gender, and causes of THA between the two groups. We evaluated the operation time, bleeding amount, incision length, ambulation, hospital stay, and complications between the two groups.

RESULTS

There was no difference in the bleeding amount between the two groups. Operation time was longer in the two-incision group than in the one-incision group. Operation time of the two-incision technique could be reduced after 15 cases. Patients started ambulation after surgery earlier in group II than group I, and the hospital stay was shorter in group II than in group I. There was no difference in clinical results between the two groups. There was no difference in component position of the acetabular cup and femoral stem between the two groups. Intraoperative periprosthetic fracture occurred in four cases (13.3%) in group II.

CONCLUSIONS

Two-incision THA has the advantage of rapid recovery and shorter hospital stay. However, longer operation time and a high complication rate compared to one-incision are problems that need to be solved in the two-incision technique.

Modified micro-superior percutaneously-assisted total hip: early experiences & case reports

Because of the extensile nature and familiarity of the standard posterior-lateral approach to the hip, a family of "micro-posterior" approaches has been developed. This family includes the Percutaneously-Assisted Total Hip (PATH) approach, the Supercapsular (SuperCap) approach and a newer hybrid approach, the Supercapsular Percutaneously-Assisted Total Hip (SuperPATH) approach. Such approaches should ideally provide a continuum for the surgeon: from a "micro" (external rotator sparing) posterior approach, to a "mini" (external rotator sacrificing) posterior approach, to a standard posterior approach. This could keep a surgeon within his comfort zone during the learning curve of the procedure, while leaving options for complicated reconstructions for the more practiced micro-posterior surgeons. This paper details one author's experiences utilizing this combined approach, as well as permutations of this entire micro-posterior family of approaches as applied to more complex hip reconstructions.

Health care transitions and the aging population: a framework for measuring the value of rapid rehabilitation

A study was undertaken to establish a framework to measure the value of rapid rehabilitation and identify indicators to quantify effective outcomes and efficient processes as health care services are delivered to the aging population across providers, services, and settings. The rapid rehabilitation protocol serving as intervention in this research provides patients (≥65 years old) the option to transition from the acute-care hospital, early in the continuum of care, to an outpatient, skilled nursing facility operated by a division of the hospital organization. A quasi-experimental, cross-sectional, retrospective study is designed to identify and quantify the relationships present in processes and outcomes inherent in health care transitions. Statistical analysis yields unexpected relationships with limited explanatory power for the selected indicators: length of stay, cost of care, discharge delays, 30-day readmissions, falls, and patient satisfaction. However, this research finds 4 imperatives for hospital and clinical leadership: (1) increase collaboration across providers, settings, and stakeholders; (2) educate workforce to optimize risk assessment of aging population; (3) standardize critical to quality measures as scientific foundation for management of services; (4) invest in technologies to ensure the integrity, validity, and reliability of information used to draw inferences about services, risk, and performance.

The economic impact of minimally invasive total hip arthroplasty

We compared hospital length of stay (LOS) and costs between (1) minimally invasive total hip surgery (MIS) combined with an active hip pathway (AHP) and (2) long incision total hip surgery (LIS) with a passive hip pathway (PHP). A prospective consecutive cohort of 214 MIS/AHP patients was compared to a concurrent cohort of 265 LIS/PHP patients. The MIS/AHP cohort had significantly decreased LOS (1.5 days vs. 3.8 days, P < .001) and hospital costs ($12.8 thousand vs. $16.7 thousand, P < .001). The complication rates were similar for MIS/AHP and LIS/PHP. We conclude that, compared to LIS/PHP, MIS/AHP significantly shortened LOS by an average of 2.3 days, and significantly reduced hospital costs by an average of $3.9 thousand per patient.

Two-incision minimally invasive total hip arthroplasty--results and complications

The purpose of this study was to determine the complication rate and functional result after two-incision minimally invasive total hip arthroplasty in a retrospective consecutive case series of the first 45 patients treated by a single surgeon. The mean follow up period was 2.1 years. There were 4 early major complications (2 peri-operative fractures and 2 re-interventions) and 28 early minor complications (1 superficial infection and 27 patients with a loss of sensation of the lateral aspect of the thigh). One stem loosening required revision within two years. The mean modified Harris Hip Score at final follow-up was 91.5. Our experience shows a relatively high complication risk after two-incision minimally invasive total hip arthroplasty, and we have since abandoned this technique.

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.

The effect of hospital volume on length of stay, re-admissions, and complications of total hip arthroplasty

BACKGROUND AND PURPOSE

Hospital volume has been suggested to be one of the best indicators of adverse orthopedic events in patients undergoing THR surgery. We therefore evaluated the effect of hospital volume on the length of stay, re-admissions, and complications of THR at the population level in Finland.

METHODS

30,266 THRs performed for primary osteoarthritis were identified from the Hospital Discharge Register. Hospitals were classified into 4 groups according to the number of THRs performed on an annual basis over the whole study period: 1-50 (group 1), 51-150 (group 2), 151-300 (group 3), and > 300 (group 4).

RESULTS

In 2005, the length of the period of surgical treatment was 5.5 days in group 4 and 6.8 days in group 1 (the reference group). During the whole study period (1998-2005), the length of surgical treatment period was shorter in group 4 than in group 1 (p < 0.001). The odds ratio for dislocations (0.7, 95% CI: 0.6-0.9) was lower in group 3 than in group 1.

INTERPRETATION

Hip replacements performed in high-volume hospitals reduce costs by shortening the length of stay, and they may reduce the dislocation rate.

Component positioning in primary total hip replacement: a prospective comparative study of two anterolateral approaches, minimally invasive versus gluteus medius hemimyotomy

INTRODUCTION

One factor of implant survivorship in total hip replacement (THR) is the quality of implant choice and positioning. The purported advantages of minimally invasive approaches are faster recovery, shorter hospital stay and less per-operative blood loss. On the other hand, there have been many reports of higher complication rates, and doubts as to the quality of implant positioning.

HYPOTHESIS

The quest to minimize tissue damage is at the cost of THR positioning quality.

OBJECTIVES

To assess implant positioning in a prospective comparative continuous multicenter series.

PATIENTS AND METHODS

Between 2008 and 2009, a prospective comparative study was conducted on a continuous series of 141 THRs. Ninety-two were performed in two centers, using a minimally invasive Watson-Jones approach; the other 49, performed in a 3rd center, used an anterolateral approach with anterior hemimyotomy. The surgeons were in all cases experienced in their technique. Short-term follow-up comprised clinical and functional (Postel Merle d'Aubigné (PMA), Harris, SF12, WOMAC) and biological assessment (serum creatine phosphokinase (CPK), myoglobinemia, hematocrit) and analysis of complications and of implant positioning on X-ray and CT-scan.

RESULTS

On the Watson-Jones approach, surgery time was longer; day-1 analgesic administration was lower; PMA, Harris and WOMAC scores were better at 6 weeks; and CPK levels were lower at 24 and 48hours. There were no significant differences on the other clinical and biological criteria. Implant positioning analysis revealed significantly greater combined anteversion and greater variation in acetabular inclination mean with the Watson-Jones approach, but no differences in cup positioning, femoral stem positioning, or limb length discrepancy.

DISCUSSION

The minimally invasive Watson-Jones approach provided faster recovery and less muscular damage. However, implant positioning was less precise in terms of acetabular cup inclination.

LEVEL OF EVIDENCE

Level III. Prospective, comparative, non-randomized.

Continuous peripheral nerve blocks in acute pain management

The indications for continuous nerve blocks for the perioperative pain management in hospitalized and ambulatory patients have extended well beyond orthopaedics. These techniques are not only used to control pain in patients undergoing major upper and lower extremity surgery, but also to provide perioperative analgesia in patients undergoing abdominal, plastic, urological, gynaecological, thoracic, and trauma surgeries. Infusion regimens of local anaesthetics and supplements must take into consideration the condition of the patient before and after surgery, the nature and intensity of the surgical stress associated with the surgery, and the possible need for immediate functional recovery. Continuous nerve blocks have proved safe and effective in reducing opioid consumption and related side-effects, accelerating recovery, and in many patients reducing the length of hospital stay. Continuous nerve blocks provide a safer alternative to epidural analgesia in patients receiving thromboprophylaxis, especially with low molecular-weight heparin.