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.     

Evidence of capsular defect following hip arthroscopy

Purpose

The purpose of this study is to identify the incidence of capsular defects in patients undergoing revision hip arthroscopy.

Methods

A radiographic and anatomical analysis of MR arthrograms of patients undergoing revision arthroscopy was performed to assess for the presence of capsular defect. Intra-operative images and findings were reviewed. Patients with persistent cam and pincer lesions were excluded.

Results

From October 2011 to October 2012, 25 patients underwent revision hip arthroscopy surgery, and 9 patients met our inclusion criteria. Within this series, all patients had post-surgical capsular irregularities and seven patients (78 %) had radiographic evidence of capsule and iliofemoral defects on MR arthrogram. Gross capsular defects were confirmed at revision surgery in two patients.

Conclusion

The findings of this study demonstrate post-surgical radiographic and anatomical evidence of capsular defects in a select group of patients following hip arthroscopy.

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.     

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.     

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.     

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.     

Increasing age and female gender are associated with early knee replacement following arthroscopy

Purpose

Early knee replacement following arthroscopy may be perceived as a failure of the original treatment and thus a poor use of resources. Factors that may be associated with increased risk of early replacement were explored in this study.

Methods

All adult patients who underwent planned knee arthroscopy in a national cohort over a 6-month period in 2005 were extracted from the administrative hospital admissions database and linked to determine whether and when a knee replacement occurred on the same knee within the subsequent 5 years. A combination of survival analysis and mixed effect modelling was used to investigate risk factors for replacement.

Results

There were a total of 20,556 arthroscopies, of which 2,161 (10.6 %) subsequently underwent knee replacement. For patients under 60 years, female gender (62.1 % higher risk, p < 0.001) and increasing age (12.7 % increased risk per increasing year of age, p < 0.001) were significant associations for requiring knee replacement, after risk adjusting. Of those aged ≥60, 12.7 % (576) had undergone a replacement at 1 year following arthroscopy. Females (33 % higher risk), increasing age (7.3 % increased risk per increasing year of age, p < 0.001) and hypertension (1,600 % higher risk, p < 0.001) were significant predictors. The risk associated with increased age was not proportional for the older age group, with risk declining as time passed from arthroscopy, indicating other factors were influencing progression to knee replacement.

Conclusions

The predictors of early knee replacement following arthroscopy were female sex, age over 60 years and hypertension, irrespective of type of operation. This work may contribute to national recommendations regarding the provision of arthroscopy for patients over 60 years.

Level of evidence

III.     

Performance outcomes in professional hockey players following arthroscopic treatment of FAI and microfracture of the hip

Purpose

Previous studies report professional athletes return to play following arthroscopic microfracture of the hip for chondral defects. Our hypothesis is that professional hockey players undergoing arthroscopic microfracture for chondral defects of the hip achieve the same performance they had pre-injury and compared to matched controls.

Methods

Seventeen professional hockey players underwent arthroscopic microfracture for an Outerbridge grade IV chondral lesion. Concomitant procedures for labral pathology or FAI were included. Performance data for the full season preceding and following index procedure were analysed, in addition to two matched control players per subject. Data were collected at two points, 2 years apart.

Results

Eighty-two per cent (14/17) of players who underwent arthroscopic microfracture returned to play. The year prior to injury for the 14 players who returned was compared to the average of their individual controls. There was no statistical difference between the groups for age, number of seasons in the league, games played, time on ice, points, save percentage, and shots against goal. Post-operatively, there was no statistical difference between the treatment and control groups regarding performance measures. There was a trend towards a decrease in games played and points post-operatively compared with controls. The treatment group decreased 11 games played, while the controls decreased five games. The treatment group also decreased 14 points, while the controls decreased three points for the season.

Conclusions

Professional hockey players with a discrete, full-thickness chondral defect of the hip are able to return to elite performance level following an arthroscopic microfracture procedure when compared to pre-injury outcomes and controls.

Level of evidence

III.     

Infection and revision rates following primary total knee arthroplasty in patients with rheumatoid arthritis versus osteoarthritis: a meta-analysis

Purpose

This meta-analysis compared infection and revision rates in patients with rheumatoid arthritis (RA) and osteoarthritis (OA) who underwent total knee arthroplasty (TKA). Rates of superficial wound and deep periprosthetic infections were compared in the groups, as were whether revision rates associated with infectious and noninfectious causes differed in the RA and OA groups.

Methods

Studies were included in the meta-analysis if they (1) compared infection and revision rates after primary TKA in RA and OA patients; (2) directly compared superficial wound and deep periprosthetic infection rates in RA and OA patients who underwent primary TKA; and (3) reported the actual numbers of RA and OA patients who underwent TKA and developed postoperative infection and/or required revision.

Results

The rate of superficial wound infections after primary TKA was similar in the RA and OA groups (15/258 [5.8 %] vs. 77/1609 [4.7 %]; odds ratio [OR] 1.12, 95 % confidence interval [CI] 0.36–3.46; P = n.n.), but the deep infection rate was significantly higher in RA than in OA patients (229/7651 [3.0 %] vs. 642/68628 [0.9 %]; OR 2.04, 95 % CI 1.37–3.05; P < 0.001). The proportion of subjects who required revision resulting from infection after TKA was significantly higher in the RA than in the OA group (86/8201 [1.0 %] vs. 555/118755 [0.5 %]; OR 1.89, 95 % CI 1,34–2.66; P < 0.001), whereas the proportion of subjects requiring revision due to noninfectious causes did not differ significantly (46/594 [7.7 %] vs. 52/904 [5.7 %]; OR 1.22, 95 % CI 0.74–2.00; P = n.n.)

Conclusion

Following primary TKA, RA patients had a significantly higher rate of deep periprosthetic infections than OA patients, but their superficial infection rates were similar. The revision rate due to infectious causes was significantly higher in RA than in OA patients, but their revision rates due to noninfectious causes did not differ. Therefore, the surgeon should fully explain to RA patients scheduled to undergo primary TKA that, compared to OA patients, they are more likely to experience a deep infection postsurgery.

Level of evidence

Meta-analysis Level III.

     

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.     

Patient reported outcome measures after revision of the infected TKR: comparison of single versus two-stage revision

Purpose

Two-stage revision is the ‘gold standard’ treatment for infected total knee replacement. Single-stage revision has been successful in the hip and, in carefully chosen knee revisions, may offer the advantage of a single surgical insult with improved functional outcome.

Methods

Patient Reported Outcome Measures (PROMs) for 33 single- and 89 two-stage revisions performed for infection were analysed in combination with data from the National Joint Registry for England and Wales. Outcomes including the Oxford Knee Score (OKS), Euroqol-5D (EQ5D) and patient satisfaction were examined with the aim of investigating the following questions: does single- or two-stage revision for infection result in (1) better knee function; (2) better overall perception of health status; (3) better patient perceived success and satisfaction?

Results

No statistical difference was found between the groups for any reported outcome measure. Mean OKS following surgery was 24.9 (95 %CI, 20.5–29.4) for single- and 22.8 (95 %CI, 20.2–25.4) for two-stage (n.s.). Mean EQ5D index following surgery was 0.495 (95 %CI, 0.357–0.632) for single and 0.473 (95 %CI, 0.397–0.548) for two-stage (n.s.). Patients reporting Excellent/Very good/Good satisfaction were similar between the groups (single = 61 % vs. two stage = 57 %, (n.s.)). In total, 66 % single- and 60 % two-stage operations were rated ‘successful’ (n.s.).

Conclusions

This study found no demonstrable benefit of single-stage compared to two-stage revision for the infected total knee replacement using a variety of PROMs. Thus, we recommend that decision making must be based on other factors such as re-infection rate.

Level of evidence

IV.     

Diagnostic accuracy of two-dimensional shear wave elastography for the non-invasive staging of hepatic fibrosis in chronic hepatitis B: a cohort study with internal validation

Objectives

To determine the accuracy of two-dimensional shear wave elastography (2D-SWE) for noninvasive staging of hepatic fibrosis in chronic hepatitis B (CHB).

Methods

Patients with CHB infection who underwent liver biopsy were consecutively included. Receiver-operating characteristic (ROC) curves were constructed to assess the overall accuracy and identify optimal cutoff values.

Results

Three hundred three patients were analysed. The diagnostic performance characteristics were determined for the first 202 patients (the index cohort) and were validated on the next 101 patients (validation cohort). The areas under the ROC curves for significant fibrosis, severe fibrosis and cirrhosis were all greater than 0.90 and did not differ significantly between the index and validation cohorts. Using the cutoff values generated from the index cohort, the validation cohort 2D-SWE had negative predictive values of 82.6 % (95 % confidence interval [CI]: 68.4 %???92.3 %) for significant fibrosis, 95.1 % (95 % CI: 86.3 %???99.0 %) for severe fibrosis and 97.4 % (95 % CI: 90.8 %???99.7 %) for cirrhosis. The positive predictive values were 83.6 % (95 % CI: 71.2 %???92.2 %), 65.0 % (95 % CI: 48.1???79.5 %) and 60.0 % (95 % CI: 38.7 %???78.9 %), respectively.

Conclusion

The 2D-SWE showed good diagnostic accuracy in staging liver fibrosis in patients with CHB infection and assisted in excluding liver fibrosis and cirrhosis.

Key Points

? Two-dimensional shear wave elastography showed good diagnostic accuracy in assessing liver fibrosis. ? Diagnostic performance did not differ significantly between the index and validation cohorts. ? Two-dimensional shear wave elastography assisted in excluding liver fibrosis and cirrhosis.     

Can hip impingement be mistaken for tendon pain in the groin? A long-term follow-up of tenotomy for groin pain in athletes

Purpose

There are several reports on the association between pubalgia and intra-articular hip disorders. The purpose of this study was to evaluate the long-term outcome in athletes who underwent tenotomy due to long-standing groin pain. A secondary purpose was evaluating the frequency of femoro-acetabular impingement (FAI) and its impact on the long-term outcome.

Methods

Thirty-two high-level male athletes treated with adductor tenotomy, rectus abdominis tenotomy or both were included. At a median follow-up time of 6 years after the tenotomy, the subjects underwent standardised clinical examination, plain radiographs, completed web-based health-related patient-reported outcomes, including iHOT12, HAGOS (six subscales), EQ-5D (two subscales), HSAS for physical activity level and a VAS for overall hip function. Furthermore, patient satisfaction and return to sports were documented.

Results

Twenty-four of the 32 (75 %) athletes were satisfied with the outcome of the tenotomy, and 22 of the athletes (69 %) were able to return to their pre-injury sport. Before the long-term follow-up, two of these satisfied athletes had undergone repeat surgery (one hip arthroscopy due to FAI and one repeat tenotomy). Of the 24 satisfied athletes, eight (33 %) had a positive hip impingement test at the follow-up. Of the remaining eight athletes not satisfied with the outcome, only one returned to their pre-injury sport and three had undergone hip arthroscopy prior to follow-up. Five had positive hip impingement tests which was significantly more frequently than in the satisfied group (p = 0.008). The group with a positive hip impingement test reported significantly more pain and symptoms, more hip problems during sports and physical activity, as well as lower hip-related quality of life according to the HAGOS scores (p < 0.05), at follow-up.

Conclusion

Tenotomy for pubalgia yielded a satisfactory long-term outcome, with three of four athletes being able to return to their pre-injury sport. The athletes that did not return to their pre-injury sport had higher frequency of positive hip impingement test and inferior functional outcome compared with the athletes that did return to their pre-injury sport. It is therefore recommended that the hip should be carefully evaluated for hip impingement before tenotomy is considered as treatment for athletes with pubalgia.

Level of evidence

Retrospective case series, Level IV.     

Mid-term survival following primary hinged total knee replacement is good irrespective of the indication for surgery

Purpose

The use of ‘hinged’ knee prostheses for primary knee arthroplasty procedures is increasing. This analysis reports the rates of implant survival, modes of failure, revision details and functional outcomes with particular reference to the primary indication for surgery for a cohort of patients treated with primary hinged knee replacement.

Methods

Systematic review with supplementary analysis using data from the National Joint Registry and Department of Health. Analysis included 964 patients undergoing primary hinged knee replacement between April 2003 and December 2010. Survival at a maximum of 7 years was calculated for the group as a whole and dependent upon the indication for surgery (osteoarthritis vs. rheumatoid/inflammatory arthritis vs. post-traumatic arthritis). Functional outcomes (pre- and post-operative Oxford Knee and Euroqol-5D scores and post-operative satisfaction) were available for 46 patients.

Results

In total, 20 cases required revision. The 5-year survival rate (96.8 % [95 % CI 95.1–98.4 %]) was not dependent upon the primary surgical indication (p = n.s.). The commonest reasons for revision were infection (8 cases), peri-prosthetic fracture (4 cases) and aseptic loosening (3 cases). Patients reported substantial improvements in their Oxford Knee Score (mean improvement = 17.6, [95 % CI 14.4–20.8]) and EQ5D index (mean improvement = 0.357, [95 % CI 0.248–0.467]). Levels of post-operative satisfaction were high.

Conclusions

Hinged knee replacement can be considered as a viable alternative to more traditional unconstrained designs in the complex primary setting. These findings are clinically relevant as they support the increasing use of hinged knee replacements for the arthritic knee in which there is concomitant severe bone loss, deformity or instability. Surgeons using these implants can have confidence that their mid-term performance is comparable to more conventional knee designs.

Level of evidence

Prospective cohort study, Level II.     

Treatment of septic arthritis of the knee: a comparison between arthroscopy and arthrotomy

Purpose

The aim of this study was to compare the efficacy of arthroscopy and arthrotomy in patients with septic monarthritis of the knee.

Methods

Seventy consecutive patients who underwent surgery because of a bacterial monarthritis were evaluated. Patients were either treated with arthroscopy or with arthrotomy. Our primary outcome was the early recurrence of infection (>3 months after surgery), which made a second surgical procedure necessary. Furthermore, the influence of potential confounders on treatment outcome was analysed.

Results

Of the 70 patients, 41 were treated arthroscopically and 29 with arthrotomy. Eight patients (11.4 %) had to undergo a second surgical procedure because of early re-infection. The rate was significantly higher in patients treated with arthrotomy (n = 6; 20.7 %) compared with those treated by arthroscopy (n = 2) (p = 0.041). Range of motion was significantly better in patients who underwent arthroscopy (p < 0.001). Male sex had negative influence on the treatment success (p = 0.03).

Conclusions

Patients with bacterial monarthritis of the knee who were treated with arthroscopy had a significantly lower re-infection rate and a better functional outcome than those treated with arthrotomy. As arthroscopy is the less invasive method, it should be considered the routine treatment, according to our data.

Level of evidence

Therapeutic study, Level III.

     

Cartilage extra-cellular matrix biomembrane for the enhancement of microfractured defects

Purpose

The purpose of the study was to evaluate whether the biomembrane made of cartilage extracellular matrix, designed to provide cartilage-like favourable environments as well as to prevent against washout of blood clot after microfracture, would enhance cartilage repair compared with the conventional microfracture technique.

Methods

A prospective trial was designed to compare the biomembrane cover after microfracture with conventional microfracture among patients with grade III–IV symptomatic cartilage defect in the knee joint. Patients aged 18–60 years were assigned to either the microfracture/biomembrane (n = 45) or microfracture groups (n = 19). Among them, 24 knees in the microfracture/biomembrane and 12 knees in the microfracture were followed up for 2 years. Cartilage repair was assessed with magnetic resonance imagings taken 6 months, 1 year, and 2 years postoperatively, and the clinical outcomes were also recorded.

Results

Compared with conventional microfracture, microfracture/biomembrane resulted in greater degree of cartilage repair (p = 0.043). In the intra-group analysis, while microfracture showed moderate to good degree of cartilage repair in nearly 50 % of the patients (47 % at 6 months to 50 % at 2 years; n.s.), microfracture/biomembrane maintained an equivalent degree of repair up to 2 years (88 % at 6 months to 75 % at 2 years; n.s.). The clinical outcome at 2 years also showed improved knee score and satisfaction and decreased pain in each group, but the difference between the two groups was not statistically significant.

Conclusions

Compared with conventional microfracture, biomembrane cover after microfracture yielded superior outcome in terms of the degree of cartilage repair during 2 years of follow-up. This implies that initial protection of blood clot and immature repair tissue at the microfractured defect is important for the promotion of enhanced cartilage repair, which may be obtained by the application of a biomembrane.

Level of evidence

Prospective comparative study, Level II.     

Adolescent patellar osteochondral fracture following patellar dislocation

Purpose

Patellar dislocations in adolescents may cause osteochondral fractures of the patella. The aim of this study was to review the outcomes of adolescent patients who underwent surgical intervention for patellar osteochondral fracture following patellar dislocation.

Methods

Nine patients who underwent surgery for osteochondral fracture of the patella following dislocation were identified retrospectively. Following arthroscopic examination, if the fragment was large enough to support fixation, headless screws or bioabsorbable pins were used. Otherwise, the loose body was excised, and the donor site was managed with a microfracture. Postoperatively, patients were assessed using the International Knee Documentation Committee (IKDC) and Knee injury and Osteoarthritis Outcome Score (KOOS) outcome measures.

Results

The average age of the patients was 14.6 with average follow-up 30.2 months. Four of the nine patients underwent fixation, while five patients underwent removal of loose body with microfracture. The average defect size in the nonfixation group was 1.2 cm² compared with 3.2 cm² in the fixation group. The IKDC scores for fixation and nonfixation groups were 63.9 (SD = 18) and 76.1 (SD = 11.7), respectively. The KOOS subscale scores for symptoms, function in sports and recreation, and knee-related quality of life were higher for the nonfixation group when compared to the fixation group.

Conclusions

This is the first known series examining surgical outcomes of osteochondral fractures of the patella following patellar dislocations in the adolescent population. While patients without fixation were less symptomatic in this series, this may be attributable to more severe injuries in patients undergoing fracture fixation.

Level of evidence

Retrospective case series, Level IV.     

Modest mid-term outcomes after isolated arthroscopic debridement of acetabular labral tears

Purpose

Currently, there is a paucity of literature regarding outcomes after isolated labral debridement. The purpose of this study was to (1) report the reoperation rate following isolated labral debridement, (2) report clinical and functional outcomes after labral debridement with a minimum 2-year follow-up and (3) identify risk factors for worse clinical and functional outcomes. It was hypothesized that inferior outcomes are associated with an increasing Tönnis grade and those with untreated femoral acetabular impingement (FAI).

Methods

The records of patients undergoing hip arthroscopy between 1998 and 2005 were reviewed. Patients with labral tears who underwent isolated arthroscopic labral debridement were identified. Kaplan–Meier estimate of failure (defined as subsequent surgery) was performed for all patients. Patients with minimum 2-year follow-up were assessed with Modified Harris Hip Score (MHHS) and Hip Outcome Score (HOS). Univariate analysis was then performed to assess which factors were associated with worse clinical and functional outcomes.

Results

Fifty-nine hips in 57 patients met our inclusion criteria (39 females, 18 males) with a mean age of 46 ± 14 years and mean follow-up of 5 (range 2–14) years. Overall, 45 % of the hips failed for repeat surgery (20 %) or rating for hip function as abnormal or severely abnormal (25 %). Twelve hips (20 %) required subsequent surgical intervention at a mean 23 (range 6–60) months (7 total hip arthroplasties, 2 open revisions, 3 arthroscopic revisions). Of the remaining hips, mean MHHS was 83.4 ± 19.7, mean HOS ADL score was 83.8 ± 21.3 and mean HOS sport score was 70.6 ± 32.9, with 33 of 41 (75 %) reporting normal or nearly normal current level of function. Univariate analysis revealed that hips with untreated bony impingement (p = 0.01) or requiring concomitant chondroplasty (p = 0.03) had inferior clinical outcome scores.

Conclusions

Isolated arthroscopic labral debridement for hip labral tears had 45 % combined poor results when strictly defining failure as repeat surgery or abnormal hip rating. Untreated FAI and concomitant chondroplasty were risk factors for inferior outcome. We recommend concomitant treatment for bony impingement lesions and preservation of the labrum whenever possible.

Level of evidence

Retrospective case series, Level IV.     

Whole-body MRI for the detection of bone marrow involvement in lymphoma: prospective study in 116 patients and comparison with FDG-PET

Objective

To assess and compare the value of whole-body MRI with FDG-PET for detecting bone marrow involvement in lymphoma.

Methods

A total of 116 patients with newly diagnosed lymphoma prospectively underwent whole-body MRI and blind bone marrow biopsy (BMB) of the posterior iliac crest. Of 116 patients, 80 also underwent FDG-PET. Patient-based sensitivities of whole-body MRI for detecting bone marrow involvement were calculated using BMB as reference standard and compared with FDG-PET in aggressive and indolent lymphomas separately.

Results

Sensitivity of whole-body MRI in all lymphomas was 45.5 % [95 % confidence interval (CI): 29.8–62.0 %]. Sensitivity of whole-body MRI in aggressive lymphoma [88.9 % (95 % CI: 54.3–100 %)] was significantly higher (P?=?0.0029) than that in indolent lymphoma [23.5 % (95 % CI: 9.1–47.8 %)]. Sensitivity of FDG-PET in aggressive lymphoma [83.3 % (95 % CI: 41.8–98.9 %)] was also significantly higher (P?=?0.026) than that in indolent lymphoma [12.5 % (95 % CI: 0–49.2 %)]. There were no significant differences in sensitivity between whole-body MRI and FDG-PET (P?=?1.00)

Conclusion

Sensitivity of whole-body MRI for detecting lymphomatous bone marrow involvement is too low to (partially) replace BMB. Sensitivity of whole-body MRI is significantly higher in aggressive lymphoma than in indolent lymphoma and is equal to FDG-PET in both entities.

Key Points

? Bone marrow involvement in lymphoma has prognostic and therapeutic implications. ? Blind bone marrow biopsy (BMB) is standard for bone marrow assessment. ? Neither whole-body MRI nor FDG-PET can yet replace BMB. ? Both techniques have higher sensitivity in aggressive than in indolent lymphoma. ? Both imaging techniques are complementary to BMB.     

A comparison of open and arthroscopic surgery for treatment of diffuse pigmented villonodular synovitis of the knee

Purpose

To compare the outcomes of diffuse pigmented villonodular synovitis (PVNS) of the knee treated with routine anteroposterior open surgery or modified multi-directional arthroscopy.

Methods

Medical records of patients with diffuse PVNS who underwent surgery between 2002 and 2010 were reviewed. Patients were followed up at 3, 6, 12, 24, and 36 months. Operative time, blood loss, length of hospital stay, recurrence rate, and International Knee Documentation Committee (IKDC) scores and Lysholm knee scores at 1- and 3-year postoperatively were compared between the open surgery and arthroscopy groups.

Results

A total of 41 patients with diffuse PVNS were included (20 in open surgery group and 21 in multi-directional arthroscopy group). There was no significant difference in the baseline characteristics between the two groups. Operation time, postoperative bleeding, and length of hospital stay were all significantly lower in the arthroscopy group than in the open surgery group (all, P < 0.05). There were four recurrences in the open surgery group and one in arthroscopy group. All five recurrences received a second surgery without any subsequent recurrences. At both 1- and 3-year postoperatively, IKDC and Lysholm scores were significantly greater in the arthroscopy group than the open surgery group (all P < 0.001).

Conclusions

The multi-directional arthroscopic technique was associated with significantly shorter operation time and hospital stay, less blood loss, and better postoperative IKDC and Lysholm scores than open surgery.

Level of evidence

Retrospective study with controls, Level III.