Fibronectin–aggrecan complex as a marker for cartilage degradation in non-arthritic hips

Purpose

To report hip synovial fluid cytokine concentrations in hips with and without radiographic arthritis.

Methods

Patients with no arthritis (Tonnis grade 0) and patients with Tonnis grade 2 or greater hip osteoarthritis (OA) were identified from patients undergoing either hip arthroscopy or arthroplasty. Synovial fluid was collected at the time of portal establishment for those undergoing hip arthroscopy and prior to arthrotomy for the arthroplasty group. Analytes included fibronectin–aggrecan complex (FAC) as well as a standard 12 cytokine array. Variables recorded were Tonnis grade, centre-edge angle of Wiberg, as well as labrum and cartilage pathology for the hip arthroscopy cohort. A priori power analysis was conducted, and a Mann–Whitney U test and regression analyses were used with an alpha value of 0.05 set as significant.

Results

Thirty-four patients were included (17 arthroplasty, 17 arthroscopy). FAC was the only analyte to show a significant difference between those with and without OA (p < 0.001). FAC had significantly higher concentration in those without radiographic evidence of OA undergoing microfracture versus those not receiving microfracture (p < 0.05).

Conclusion

There was a significantly higher FAC concentration in patients without radiographic OA. Additionally, those undergoing microfracture had increased levels of FAC. As FAC is a cartilage breakdown product, no significant amounts may be present in those with OA. In contrast, those undergoing microfracture have focal area(s) of cartilage breakdown. These data suggest that FAC may be useful in predicting cartilage pathology in those patients with hip pain but without radiographic evidence of arthritis.

Level of evidence

Diagnostic, Level III.     

Intra-articular adhesions following hip arthroscopy: a risk factor analysis

Purpose

The purpose of this study was to evaluate possible risk factors for symptomatic adhesions after hip arthroscopy.

Methods

Data were analysed from hip arthroscopies performed between 2005 and 2009. Only primary hip arthroscopies were included. Data collected included demographics, primary treatment, rehabilitation, revision surgery, and presence of adhesions at revision.

Results

One thousand two hundred and sixty-four hips in patients 18 years or older underwent primary hip arthroscopy during the defined period. Eight underwent revision hip arthroscopy by a different surgeon. Patients under 30 years of age were 5.9 times more likely to be in the adhesion group [95 % CI 3.1–11.5]. Patients who underwent microfracture were 3.1 times less likely to have adhesions compared to patients who did not [95 % CI 1.1–8.2]. Patients who did not receive circumduction therapy were 4.1 times more likely to have adhesions compared to those who performed circumduction exercises [95 % CI 1.25–11.0].

Conclusion

Risk factors for adhesions following hip arthroscopy identified were age under 30, modified Harris Hip score under 50, no microfracture performed, and rehabilitation without circumduction.

Level of evidence

IV.     

Revision hip arthroscopic surgery: outcome at three years

Purpose

This study describes the medium-term results of revision hip arthroscopy.

Methods

Patients with persistent hip pain and a positive impingement sign were considered for revision surgery after the exclusion of other causes of groin pain. Seventy-four consecutive patients were prospectively assessed using the modified Harris hip score for a period of 3 years after surgery. Of the 74 patients, 11 had inadequate follow-up data; thus, a total of 63 patients were qualified for the study. The mean age at index surgery was 37 years, comprising 27 males and 36 females.

Results

Revision surgery was performed at a mean of 3 years from index surgery. Chondral lesion associated with labral re-injury was the most common finding at revision arthroscopy. In contrast to other authors, however, only 31 % of our patients underwent revision for persistent femoroacetabular impingement. The mean pre-operative mHHS for all 63 patients was 54 (SD 14.5). The mean post-operative mHHS was 53 (SD 14.9) at 6 weeks, 62 (SD 17.5) at 6 months, 63 (SD 16.5) at 1 year, 64 (SD 16.5) at 2 years and 59 (SD 16.5) at 3 years (p = n.s., 0.02, 0.045, 0.039 and n.s., respectively).

Conclusions

Revision arthroscopy results in improvement in outcome in the first 3 years after revision surgery with a success rate of 63.4 % at 1 year, falling to 55.6 % by 3 years.

Level of evidence

IV.     

MR-arthrography in superior instability of the shoulder: correlation with arthroscopy

Purpose

This study was undertaken to evaluate magnetic resonance (MR) arthrography in the detection and classification of lesions that may cause superior instability.

Materials and methods

Forty-two consecutive patients with clinical signs of chronic superior instability of the shoulder underwent MR arthrography followed by arthroscopic surgery. For each patient we retrospectively reviewed the MR arthrography and surgical findings.

Results

We detected 31 superior labral anterior posterior (SLAP) lesions, all confirmed on arthroscopy with three cases of underestimation: in the detection of SLAP lesions, the sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of MR arthrography were 100%; in the evaluation of the type of SLAP lesion, sensitivity was 100%, specificity was 78.5%, accuracy was 92.8%, PPV was 71.7% and NPV was 100%. All cases of capsular laxity (13/42) and biceps tendon lesions (3/42) were confirmed on arthroscopy with sensitivity, specificity, accuracy, PPV and NPV of 100%. Eleven cuff lesions were detected on MR arthrography, 10 of which confirmed at arthroscopy: sensitivity was 100%, specificity was 96.8%, accuracy was 97.6%, PPV was 90.9% and NPV was 100%. Associated lesions were found in 38/42 patients.

Conclusions

Superior instability is frequently associated with different anatomical variants or pathological conditions, such as SLAP lesions. The role of MR arthrography is to describe the key features of lesions affecting the superior portion of the shoulder, including location, morphology, extent, and associated injuries and leanatomical variants and to correlate these features with clinical symptoms.     

Arthroscopic treatment for acute septic arthritis of the hip joint in adults

Purpose

The purpose of our study was to evaluate the efficacy and safety of the arthroscopic management of septic arthritis of the hip joint.

Methods

From October 2009 to October 2010, nine patients with septic arthritis of the hip were treated with arthroscopic debridement and drainage and systemic antibiotics according to bacterial sensitivity or with empiric antibiotics if no bacteria was isolated from the cultures. All patients were placed in the supine position on a fracture table, and two or three arthroscopic portals were used. The medical records were retrospectively reviewed to determine the efficacy and safety of hip arthroscopy for septic arthritis.

Results

There were 4 men and 5 women, with a mean age of 49.8 years (SD 12.1). No major complication related to arthroscopy of the hip was encountered. Staphylococcus aureus was identified in 4 patients. Average follow-up was 19.4 months (SD 4.1). Septic arthritis relapsed in one patient, but the other 8 patients experienced no recurrence during the follow-up period.

Conclusions

Arthroscopic lavage and debridement is a safe and effective procedure for septic arthritis of the hip joint.

Level of evidence

IV.     

Comparison of 3.0-T MR vs 3.0-T MR arthrography of the hip for detection of acetabular labral tears and chondral defects in the same patient population

Objective:

We report our experience in diagnostic sensitivity of 3.0-T conventional MR vs 3.0-T MR arthrography of the hip for detection of acetabular labral tears and chondral defects in the same patient population.

Methods:

43 consecutive patients had both conventional hip MR and MR arthrography examinations performed. These examinations were reviewed retrospectively by independent reading of two musculoskeletal radiologists who read the MR and MR arthrogram examinations in a randomized fashion (i.e. MR and MR arthrogram examinations were read at separate sittings and in a randomized fashion so as not to bias reviewers). Scans were assessed for acetabular labral tears and chondral defects. All patients went on to arthroscopy.

Results:

Of these 43 patients, 40 had acetabular labral tears read by Reader 1 and 39 had acetabular labral tears read by Reader 2 on MR arthrogram, 39 had acetabular labral tears read by Reader 1 and 38 had acetabular labral tears read by Reader 2 on conventional MR examination. There were 42 labral tears in 43 patients at arthroscopy. There were four false-negative labral tears compared with arthroscopy on MR and three false negatives on MR arthrography for Reader 1 and five false negatives on MR and four false negatives on MR arthrography for Reader 2. Each reader had one false-positive labral tear compared with arthroscopy on both MR and MR arthrography. There were 32 acetabular chondral defects at arthroscopy. Reader 1 saw 21 acetabular chondral defects on conventional MR and 27 chondral defects at MR arthrography. Reader 2 saw 19 acetabular chondral defects at conventional MR and 25 acetabular chondral defects on MR arthrography. There were no false-positive readings of chondral defects compared with arthroscopy on MR and one false positive for Reader 1 and two false positives for Reader 2 on MR arthrography as compared with arthroscopy. On conventional MR examination, sensitivities and specificities as compared with arthroscopy were as follows: Reader 1 acetabular labral tear (90% sensitivity, 0% specificity) and Reader 2 acetabular labral tear (88% sensitivity, 0% sensitivity). On MR arthrogram, sensitivities and specificities as compared with arthroscopy for Reader 1 were 93%, 0% and for Reader 2 were 90%, 0%, respectively. Sensitivities and specificities for detection of acetabular chondral defects as compared with arthroscopy were Reader 1 conventional MR (65% sensitivity, 100% specificity), Reader 1 MR arthrography (81% sensitivity, 91% specificity), Reader 2 conventional MR (59% sensitivity, 100% specificity) and Reader 2 MR arthrography (71% sensitivity, 82% specificity).

Conclusion:

In this series, 3.0-T MR demonstrated sensitivity for detection of acetabular labral tears that rivals the sensitivity of 3.0-T MR arthrography of the hip. In this series, 3.0-T MR arthrography was more sensitive than conventional 3.0-T MR for detection of acetabular chondral defects.

Advances in knowledge:

3.0-T MR and MR arthrography are near equivalent in the diagnosis of acetabular labral tears. This information is useful for pre-operative planning.MR arthrography has been reported to be more sensitive and specific for detection of acetabular labral tears in the hip than conventional MRI.^1–10 MR arthrography has also been reported to be superior in detection of acetabular cartilage defects as compared with conventional MRI.¹¹ To our knowledge 3.0-T MR vs 3.0-T MR arthrography sensitivity for detection of acetabular labral tears and chondral defects has not been specifically assessed.To our knowledge, Petersilge et al¹ first reported the utility of hip MR arthrography in the diagnosis of acetabular labral tears. Toomayan et al² compared MR arthrography of the hip with conventional MRI of the hip in different patient populations. He found MR arthrography with a small field of view to be substantially more sensitive for detection of acetabular labral tears than conventional MRI. Sutter et al¹¹ found 1.5 T MR arthrography to be superior to conventional MRI for detecting labral tears and acetabular cartilage defects.Patients with acetabular labral tears present with symptoms of persistent pain, clicking, locking and decreased range of motion. With the availability of hip arthroscopy, labral tears can more easily be addressed with minimally invasive surgery. Accurate pre-operative identification of labral tears is needed.² Based on previous studies demonstrating the accuracy of MR arthrography in detection of acetabular labral tears, surgeons often request MR arthrography of the hip to characterize labral tears prior to surgery.^1–10 The purpose of this study is to assess 3.0-T MR vs MR arthrography diagnostic performance in detection of acetabular labral tears and chondral defects in the same patient population using arthroscopy as a reference standard.     

MR versus MR arthrography in detection of supraspinatus tendon tears in patients without previous shoulder surgery

Purpose

We report the prevalence of supraspinatus tendon tears seen on MR arthrography that are not seen on conventional MR exam in the same patient population.

Materials and methods

A total of 150 consecutive conventional shoulder MR and MR arthrography exams performed on the same patients who went on to arthroscopy were reviewed retrospectively by consensus reading of two musculoskeletal radiologists. Full-thickness supraspinatus tendon tears were assessed. None of the patients had previous shoulder surgery.

Results

There were 113 full-thickness supraspinatus tendon tears seen on conventional MR exam while there were 119 full-thickness supraspinatus tendon tears seen on MR arthrography. The six additional full-thickness supraspinatus tendon tears seen on MR arthrography but not seen on conventional MR exam were confirmed at arthroscopy.

Conclusions

Some full-thickness supraspinatus tendon tears are not seen on conventional MR exam but are seen on MR arthrography. This is most likely due to fibrosis at the supraspinatus tendon tear site simulating an intact tendon on conventional MR.     

Utility of multimodal analgesia with fascia iliaca blockade for acute pain management following hip arthroscopy

Purpose

The purpose of this study was to evaluate the utility of multimodal analgesia with fascia iliaca blockade and for acute pain control in patients undergoing hip arthroscopy.

Methods

Thirty consecutive patients undergoing primary hip arthroscopy were prospectively studied. All patients were treated preoperatively with ultrasound-guided single injection fascia iliaca blockade and multimodal analgesia. Data collected included post-operative nausea, numeric rating scale (NRS) pain scores during rest and activity, opioid consumption during the first five days (recorded as tablets of 5 mg hydrocodone/500 mg acetaminophen) and overall patient satisfaction with analgesia.

Results

This study included 23 female and 7 male patients with a median age of 35 years (range 14–58). No patient required medication for post-operative nausea. The overall NRS scores were an average of 3.9 on day 0, 3.6 on day 1, 3.4 on day 2, 2.9 on day 3, 3.0 on day 4 and 2.7 on day 5. The average tablets of opioid taken were 1.5 on day 0, 1.2 on day 1, 1.3 on day 2, 1.0 on day 3, 1.1 on day 4 and 0.9 on day 5. Overall, 20 patients rated their post-operative pain control as very satisfied (67 %), and 10 patients as satisfied (33 %). There were no complications or side effects from the fascia iliaca blockade.

Conclusion

In this prospective study, multimodal analgesia with fascia iliaca blockade following hip arthroscopy was safe and effective. The quality of early post-operative analgesia provided by the fascia iliaca blockade was excellent and resulted in low opioid consumption, high quality of pain relief and high overall patient satisfaction.

Level of evidence

Prospective case series, Level II.     

Complications following hip arthroscopy: a systematic review and meta-analysis

Purpose

The use of hip arthroscopy to address injuries and conditions about the hip is becoming more widespread. There are several narrative reviews regarding complications of hip arthroscopy but a systematic review is currently lacking. The primary goal of this study is to determine the complication rate associated with hip arthroscopy in the literature.

Methods

A search of the EMBASE and Ovid Medline databases was performed to identify articles published between 1 January 2000 and 25 November 2011 that reported a complication rate after hip arthroscopy. Appropriate inclusion and exclusion criteria were applied to identify articles, and a meta-analysis was performed to determine an overall complication rate. Complications were divided into major and minor.

Results

A total of 66 papers (n = 6,962 hip arthroscopies) were identified and deemed appropriate for analysis. The overall complication rate was found to be 4.0 % (95 % CI 2.9–5.2 %). Of the 287 complications identified in the literature, 20 were deemed major constituting a rate of 0.3 %.

Conclusions

Hip arthroscopy appears to be safe. The vast majority of complications are minor in nature. Prospective trials looking at the complications of hip arthroscopy would aid in identifying prognostic factors.

Level of evidence

Systematic review and meta-analysis, Level III.     

Accuracy of 3-Tesla MR and MR arthrography in diagnosis of meniscal retear in the post-operative knee

Purpose

This study assesses the accuracy of 3-Tesla (3-T) conventional MR imaging, 3-T MR arthrography, and the combined use of conventional MR and MR arthrography in the diagnosis of meniscal retears as compared with arthroscopy. The study also assess whether there are false-negative cases in which injected contrast does not extend into the meniscus despite a meniscal retear being seen on arthroscopy.

Materials and methods

One hundred consecutive knee MR arthrograms performed on patients with previous knee surgery were reviewed retrospectively. 3-T conventional MR imaging, 3-T MR arthrography, and the combined use of conventional MR and MR arthrography were assessed for meniscal retears as compared with arthroscopy. The criterion used to diagnose a meniscal retear on MR arthrogram was injected contrast tracking into the meniscus. All patients underwent second-look arthroscopy.

Results

Seventy-four patients had conventional MR findings consistent with a meniscal retear. In 83 of the 100 patients, intraarticular contrast helped in demonstrating a retear. In ten patients, there were MR findings consistent with a meniscal retear despite intra-articular contrast not tracking into the meniscus. Ninety-four of the 100 patients had meniscal retears on second-look arthroscopy. Three-Tesla conventional MR examination was 78 % sensitive and 75 % specific, MR arthrogram examination was 88 % sensitive and 100 % specific, and the combined use of MR and MR arthrogram imaging was 98 % sensitive and 75 % specific in the diagnosis of a meniscal retear.

Conclusions

The combined use of 3-T MR and MR arthrography allows for high sensitivity and specificity in meniscal retear detection. In some patients, intraarticular contrast will not track into a meniscal retear. When MR findings are consistent with a meniscal retear but contrast does not extend into the meniscus, a meniscal retear is likely.     

A comprehensive five-phase rehabilitation programme after hip arthroscopy for femoroacetabular impingement

Purpose

Recent advancements in the understanding of hip biomechanics have led to the development of techniques to remove bony impingement and repair and/or preserve the labrum during hip arthroscopy. Although much attention in the literature is devoted to diagnosis and treatment, there is little information about post-operative rehabilitation. Therefore, the purpose of this review is to (1) provide a five-phase rehabilitation protocol following arthroscopic treatment for FAI and (2) report clinical and functional outcomes of patients following this protocol at minimum 1-year follow-up, in order to provide the surgeon and therapist with a protocol that is supported by clinical data.

Methods

All consecutive patients undergoing hip arthroscopy and subsequent five-phase rehabilitation protocol at a single institution from 1 April 2011 to 1 April 2012 were analysed. Inclusion criteria were as follows: no prior ipsilateral hip surgery, completion of the five-phase rehabilitation protocol, minimum 1-year follow-up, and documented outcome scores. Prospective outcomes were assessed with modified Harris hip score (MHHS) and hip outcome score (HOS).

Results

Fifty-two patients (19 male and 33 female) met the inclusion criteria with a median age of 42 (range 16–59) years. Mean MHHS, HOS-ADL, and HOS-sport scores at a mean 12.5 (range 12–15) months were 80.1 ± 19.9 (0–100), 83.6 ± 19.2 (13.2–100), and 70.3 ± 27.0 (0–100), respectively.

Conclusion

This five-phase rehabilitation programme provides a framework where progression from surgery to increasing post-operative activity level can take place in a predictable manner. Patients following this rehabilitation protocol after hip arthroscopy demonstrated satisfactory clinical and functional outcomes, validating its implementation.

Level of evidence

Case series, Level IV.     

The reharvested patellar tendon has the potential for ligamentization when used for anterior cruciate ligament revision surgery

Purpose

The aim of the present study was to make an in-depth clinical, radiographical, and histological evaluation of patients who underwent anterior cruciate ligament (ACL) revision surgery with reharvested central third patellar tendon autograft.

Methods

Four patients (two women and two men) underwent ACL revision surgery with reharvested patellar tendon autograft 71 (66–120) months after the primary reconstruction. The patients were followed prospectively and underwent a clinical examination and magnetic resonance imaging (MRI) at two and 10 years. Furthermore, they underwent a second-look arthroscopy involving a biopsy procedure from the reconstructed ACL 3 years after revision surgery.

Results

The clinical results were poor both at two and 10 years, but the knees were stable and had a firm endpoint in all four patients in the Lachman test. At the second-look arthroscopy, the graft appeared macroscopically normal in all four patients. Histologically two patients had a normal or close to normal appearance of the reconstructed ACL with no or slight increase in cellularity and vascularity. Two patients had a marked increase in cellularity and vascularity, and the findings revealed that ligamentization was present in all four patients.

Conclusions

The clinical outcome 10 years after ACL revision surgery was poor in these four patients. In contrast, the reharvested patellar tendon appeared close to normal on MRI, and the second-look arthroscopy with the concomitant histological findings revealed that the grafts were viable 3 years after revision. Therefore, the reharvested patellar tendon seems to have the potential for ligamentization when used for ACL revision surgery.

Level of evidence

Case series, Level IV.     

A multimodal approach in total hip arthroplasty preoperative templating

Objectives

Accurate preoperative planning is mandatory for a successful total hip arthroplasty (THA). Templating helps to achieve multiple technical goals, including offset restoration, leg-length equality, and components positioning. This study aims to measure how successful a new stepwise method for preoperative radiographic templating is in achieving postoperative restoration of anatomy.

Methods

We measured the relationship of several radiographic landmarks on the affected limb in comparison to the unaffected limb to define the appropriate position of the components. One hundred consecutive patients with unilateral disease undergoing THA were retrospectively analyzed. The preoperative templates were compared with the postoperative radiographs.

Results

Accuracy in achieving the desired offset, leg-length discrepancy within 5 mm, was 93 % and 100 % respectively. Acetabular component positioning within 2° was replicated in 92 %.

Conclusion

We conclude that this technique can help the surgeon to accurately reproduce the anatomy of the contralateral unaffected hip.     

A Swedish hip arthroscopy registry: demographics and development

Purpose

Hip arthroscopy is a rapidly expanding field in orthopaedics. Indications and surgical procedures are increasing. Although several studies report favourable clinical outcomes, further scientific evidence is needed for every aspect of this area. Accordingly, a registry for hip arthroscopy was developed. The purpose of this study is to describe the development of the registry and present its baseline data.

Methods

A Scandinavian expert group agreed to use a set of functional outcome scores for the evaluation of hip arthroscopy patients. They were the international hip outcome tool-12, hip and groin outcome score, EQ-5D, hip-specific activity level scale and visual analogue scale for overall hip function. These scores were validated and culturally adapted to Swedish. A database was created for web-based, self-administered questionnaires. Perioperative data were also collected.

Results

The process leading to the registry is reported. Baseline data from the first 606 patients collected during a 14-month period are presented. The preferred surgical technique is presented. The mean operation time was 69 (SD 14) minutes. In 333 procedures, mixed cam and pincer pathology were addressed, compared with 223 procedures with the treatment of isolated cam pathology. Outpatient surgery was performed in all patients.

Conclusion

The baseline data in this study can be used as reference values for future scientific work from this registry. Knowledge of the process leading to the development of the registry could be useful to other researchers planning similar work.

Level of evidence

IV.     

The adductor tubercle as an important landmark to determine the joint line level in total knee arthroplasty: from radiographs to surgical theatre

Purpose

The restoration of the normal joint line (JL) is important both in primary and revision total knee arthroplasty (TKA). However, the assessment of the femoro-tibial JL is still controversial. A strong correlation between femoral width (FW) and distance from adductor tubercle (AT) to JL was found on radiographs, with a ratio of 0.54. The hypothesis was that this ratio was applicable also in the surgical theatre by using measurements obtained intra-operatively with a caliper.

Methods

Femoral width, AT to JL distance and the RATIO between AT to JL distance and FW of 40 patients who underwent TKA were measured on radiograph and intra-operatively. Bland–Altman agreement tests with repeated measurements and linear regression analysis were used. The ratio was used to estimate the distance between JL and AT.

Results

The AT to JL distance/FW ratio calculated with linear regression resulted 0.54 for radiographic measurements and 0.53 for intra-operative measurements. There was no difference (0.009 ± 0.03) between the calculated ratios on radiographic and intra-operative measurements, and the correlation between intra-operative and radiographic measurements was 0.5 (p = 0.0016).

Conclusions

This study shows that the validity of the radiographic method which uses an AT to JL distance/FW ratio to determine the level of the JL is confirmed also when using intra-operatively acquired measurements. Thus, this ratio represents a reliable tool to determine the JL level even in challenging prosthetic revision cases when the anatomical JL is missing.

Level of evidence

Case series, Level IV.     

Revision ACL reconstruction using contralateral hamstrings

Purpose

Due to the increasing number of primary anterior cruciate ligament (ACL) reconstructions, the need for revision surgery has risen. The aim of this study was to evaluate the use of contralateral doubled semitendinosus and gracilis tendon (DGST) for revision anterior cruciate ligament reconstruction.

Methods

Twelve patients undergoing revision ACL reconstruction with hamstring tendon were examined at an average follow-up of 3 years. All patients underwent a thorough subjective and objective evaluation, which included a KT-1000 arthrometric evaluation, and a radiographic examination.

Results

Subjective evaluation yielded a median score of 5.5 (range 2–9) on the Tegner activity scale. The mean Lysholm score was 95 (SD 9.5), and the mean subjective IKDC 2000 score was 95.4 (SD 7.8). At physical examination, a negative Lachman test was found in ten patients; one patient had a positive Lachman test with a firm end-point, and one other patient had a clearly positive Lachman test. Two patients had a grade 1+ on pivot shift testing. Only 1 patient showed a side-to-side difference more than 5 mm at the maximum manual KT-1000 arthrometer. Three patients (25 %) showed initial signs of osteoarthritis.

Conclusions

The results of the study show that the use of hamstring tendons harvested from the unaffected knee represents a valid option for revision surgery following a failed primary ACL reconstruction using DGST grafts.

Level of evidence

IV.     

Learning curve of basic hip arthroscopy technique: CUSUM analysis

Purpose

Hip arthroscopy is known to have a steep learning curve by measuring operation times or complication rates. However, these measures are arbitrary and are based on the number of procedures performed rather than clinical outcomes. Recently, Cumulative sum (CUSUM) analysis has been used to monitor the performance of a single surgeon by evaluating clinical outcomes. Our purpose was to determine the learning curve for basic hip arthroscopy technique using CUSUM technique.

Methods

Forty consecutive patients who underwent hip arthroscopy were evaluated. Modified Harris Hip Score less than 80 at 6 months postoperatively was considered as treatment failure. Patients were chronologically stratified in two groups (the early group—cases 1–20, and the late group—cases 21–40), and age, gender, body mass index, and operation time were compared in both group. CUSUM analysis was then used to plot the learning curve.

Results

Eight patients (20 %) experienced treatment failure. Although there was no significant difference of treatment failure rate between the early and late groups (30 vs. 10 %, n.s.), the operation time was shorter in the late group (p = 0.014). In addition, CUSUM analysis showed that failure rates diminished rapidly after 21 cases and reached an acceptable rate after 30 cases.

Conclusions

Surgeon’s experience is an important predictor of failure after hip arthroscopy, and CUSUM analysis revealed that a learning period is required to become proficient at this procedure, and that experience of approximately 20 cases is required to achieve satisfactory outcomes in terms of clinical outcomes. Surgeon can use the present learning curve for self-monitoring and continuous quality improvement in hip arthroscopy.

Level of evidence

Retrospective case series, Level IV.     

Utility of percutaneous joint aspiration and synovial biopsy in identifying culture-positive infected hip arthroplasty

Purpose

Percutaneous synovial biopsy has recently been reported to have a high diagnostic value in the preoperative identification of periprosthetic infection of the hip. We report our experience with this technique in the evaluation of patients undergoing revision hip arthroplasty, comparing results of preoperative synovial biopsy with joint aspiration in identifying an infected hip arthroplasty by bacteriological analysis.

Materials and methods

We retrospectively reviewed the results of the 110 most recent revision hip arthroplasties in which preoperative synovial biopsy and joint aspiration were both performed. Revision surgery for these patients occurred during the period from September 2005 to March 2012. Using this study group, results from preoperative cultures were compared with preoperative laboratory studies and the results of intraoperative cultures. Synovial aspiration was done using an 18- or 20-gauge spinal needle. Synovial biopsy was done coaxially following aspiration using a 22-gauge Chiba needle or 21-gauge Sure-Cut needle. Standard microbiological analysis was performed on preoperative synovial fluid aspirate and synovial biopsy. Intraoperative tissue biopsy bacteriological analysis results at surgical revision were accepted as the “gold standard” for the presence or absence of infection.

Results

Seventeen of 110 (15 %) of patients had intraoperative culture-positive periprosthetic infection. Of these 17 cases, there were ten cases where either the synovial fluid aspiration and/or the synovial biopsy were true positive (sensitivity of 59 %, specificity of 100 %, positive predictive value of 100 % and accuracy of 94 %). There were seven cases where aspiration and biopsy results were both falsely negative, but no false-positive results. Similar results were found for synovial fluid aspiration alone. The results of synovial biopsy alone resulted in the identification of seven infected joints with no false-positive result (sensitivity of 41 %, specificity of 100 %, positive predictive value of 100 %, and accuracy of 91 %).

Conclusions

Standard microbiological analyses performed on percutaneous synovial biopsy specimen during the preoperative evaluation of patients undergoing revision hip arthroplasty did not improve detection of culture-positive periprosthetic infection as compared to synovial fluid aspiration alone.     

Capability of differentiating smokers with normal pulmonary function from COPD patients: a comparison of CT pulmonary volume analysis and MR perfusion imaging

Objective

To compare CT volume analysis with MR perfusion imaging in differentiating smokers with normal pulmonary function (controls) from COPD patients.

Methods

Sixty-two COPD patients and 17 controls were included. The total lung volume (TLV), total emphysema volume (TEV) and emphysema index (EI) were quantified by CT. MR perfusion evaluated positive enhancement integral (PEI), maximum slope of increase (MSI), maximum slope of decrease (MSD), signal enhancement ratio (SER) and signal intensity ratio (R_SI) of perfusion defects to normal lung.

Results

There were 19 class I, 17 class II, 14 class III and 12 class IV COPD patients. No differences were observed in TLV, TEV and EI between control and class I COPD. The control was different from class II, III and IV COPD in TEV and EI. The control was different from each class of COPD in R_SI, MSI, PEI and MSD. Differences were found in R_SI between class I and III, I and IV, and II and IV COPD. Amongst controls, MR detected perfusion defects more frequently than CT detected emphysema.

Conclusions

Compared with CT, MR perfusion imaging shows higher potential to distinguish controls from mild COPD and appears more sensitive in identifying abnormalities amongst smokers with normal pulmonary function (controls).

Key Points

? Detailed information is needed to diagnose chronic obstructive pulmonary disease. ? High-resolution CT provides detailed anatomical and quantitative information. ? Magnetic resonance imaging is demonstrating increasing potential in pulmonary function imaging. ? MR perfusion can distinguish mild COPD patients from controls. ? MRI appears more sensitive than CT in identifying early abnormalities amongst controls.     

Complications in ankle arthroscopy

Purpose

To determine the complication rate for ankle arthroscopy.

Methods

A review of a consecutive series of patients undergoing ankle arthroscopy in our hospital between 1987 and 2006 was undertaken. Anterior ankle arthroscopy was performed by means of a 2-portal dorsiflexion method with intermittent soft tissue distraction. Posterior ankle arthroscopy was performed by means of a two-portal hindfoot approach. Complications were registered in a prospective national registration system. Apart from this complication registry, patient records, outpatient charts and operative reports were reviewed. Patients with a complication were asked to visit our hospital for clinical examination and assessment of permanent damage and persisting complaints.

Results

An overall complication rate of 3.5?% in 1,305 procedures was found. Neurological complications (1.9?%) were related to portal placement. Age was a significant risk factor for the occurrence of complications. Most complications were transient and resolved within 6?months. Complications did not lead to functional limitations. Residual complaints did not influence daily activities.

Conclusions

Our complication rate is less than half of what has been reported in literature (3.5 vs 10.3?%). The use of the dorsiflexion method for anterior ankle arthroscopy can prevent a significant number of complications. Posterior ankle arthroscopy by means of a two-portal hindfoot approach is a safe procedure with a complication rate that compares favourably to that of anterior ankle arthroscopy.

Level of evidence

Retrospective prognostic study, Level II.