Complications After Arthroscopic Knee Surgery

Background: Knee arthroscopies are among the most common procedures performed by orthopaedic surgeons, yet little is known about the associated complications and complication rates. 

Purpose: To examine the nature and frequency of complications after the most common arthroscopic knee procedures, with particular attention to fellowship training, geographic location of practice, and age and sex of the patient. 

Study Design: Cross-sectional study; Level of evidence, 3. 

Methods: Data were obtained from the American Board of Orthopaedic Surgery database for orthopaedic surgeons who sat for the part II examination from 2003 to 2009. The database was queried to determine the type and frequency of complications for patients who underwent knee arthroscopy and for those who underwent sports medicine knee arthroscopy, including arthroscopic partial meniscectomy, meniscal repair, chondroplasty, microfracture, anterior cruciate ligament reconstruction, or posterior cruciate ligament reconstruction. Factors affecting complication rates that were investigated included type of procedure, fellowship training status, geographic location of practice, and age and sex of the patient. 

Results: There were 4305 complications out of 92,565 knee arthroscopic procedures obtained from the American Board of Orthopaedic Surgery database for an overall candidate-reported complication rate of 4.7%. The complication rates were highest for posterior cruciate ligament reconstruction (20.1%) and anterior cruciate ligament reconstruction (9.0%); complication rates for meniscectomy, meniscal repair, and chondroplasty were 2.8%, 7.6%, and 3.6%, respectively. The complication rate for sports fellowship–trained candidates was higher than for non–sports trained candidates (5.1% sports, 4.1% no sports; P < .0001) and for male patients (4.9% male vs 4.3% female; P < .0001). Younger patients (<40 years; 6.2%) had a higher complication rate than older patients (≥40 years; 3.58%) (P < .0001). Procedure complexity is a likely confounding factor affecting sports-trained candidates and younger patients. There were no geographic differences (P = .125). The overall rate of pulmonary embolus was 0.11%. Surgical complications (3.68%) were more common than medical (0.77%) or anesthetic complications (0.22%), and infection was the most common complication overall (0.84%). 

Conclusion: The overall self-reported complication rate for arthroscopic knee procedures was 4.7%. Knee arthroscopy is thought not to be a benign procedure, and patients should be made aware of the risk of complications. 

Comment:
Please note that the article reflects the figures for fellowship trainees. They may be different in the group of a specialised surgeon. However, the range of complications and their proportions may be the same.

  

Salzler MJ et al. Complications After Arthroscopic Knee Surgery. Am J Sports Med 2013; online 27. November; doi: 10.1177/0363546513510677

"Red flags" under fire

Most clinical practice guidelines for back pain recommend the use of red flags to help identify those patients with a higher likelihood of spinal fracture or malignancy who then become candidates for more extensive diagnostic investigations. There is confusion, however, as the guidelines have produced different lists of red flags to screen for spinal fracture and malignancy. Eight of the guidelines investigated by Koes and colleagues in their review of back pain guidelines, endorsed 26 red flags for fracture and 27 for malignancy. 

None of the eight guidelines endorsed the same set of red flags, for either condition, so it is unclear what clinicians should use in clinical care. Additionally, guidelines generally provide no information on diagnostic accuracy of the endorsed red flags, which limits their value in clinical decision making. Adding to the uncertainty, the same agency can provide inconsistent information on red flags. For example, the National Institute for Health and Care Excellence clinical guideline on the early management of persistent non-specific low back pain does not endorse red flags, whereas the group’s clinical knowledge summary for the management of low back pain does

To resolve the uncertainty around application of red flags in clinical practice, the authors conducted two Cochrane diagnostic test accuracy reviews assessing the accuracy of red flags to screen for the most common forms of serious pathology—spinal fracture and malignancy—in patients with low back pain. They have provided a distilled summary of both reviews to help guide clinical decision making.

Objective To review the evidence on diagnostic accuracy of red flag signs and symptoms to screen for fracture or malignancy in patients presenting with low back pain to primary, secondary, or tertiary care.

Design Systematic review.

Data sources Medline, OldMedline, Embase, and CINAHL from earliest available up to 1 October 2013.

Inclusion criteria Primary diagnostic studies comparing red flags for fracture or malignancy to an acceptable reference standard, published in any language.

Review methods Assessment of study quality and extraction of data was conducted by three independent assessors. Diagnostic accuracy statistics and post-test probabilities were generated for each red flag.

Results We included 14 studies (eight from primary care, two from secondary care, four from tertiary care) evaluating 53 red flags; only five studies evaluated combinations of red flags. Pooling of data was not possible because of index test heterogeneity. Many red flags in current guidelines provide virtually no change in probability of fracture or malignancy or have untested diagnostic accuracy. The red flags with the highest post-test probability for detection of fracture were older age (9%, 95% confidence interval 3% to 25%), prolonged use of corticosteroid drugs (33%, 10% to 67%), severe trauma (11%, 8% to 16%), and presence of a contusion or abrasion (62%, 49% to 74%). Probability of spinal fracture was higher when multiple red flags were present (90%, 34% to 99%). The red flag with the highest post-test probability for detection of spinal malignancy was history of malignancy (33%, 22% to 46%).

Conclusions While several red flags are endorsed in guidelines to screen for fracture or malignancy, only a small subset of these have evidence that they are indeed informative. These findings suggest a need for revision of many current guidelines.

Read the article:

BMJ 2013;347:f7095 BMJ 2013; 347 doi: http://dx.doi.org/10.1136/bmj.f7095 (Published 11 December 2013). 

Excise or save: Do we need a fat pad?

The infrapatellar fat pad is one of the structures that obscures exposure in minimally invasive total knee arthroplasty (MIS TKA). Most MIS TKA surgeons (and many surgeons who use other approaches as well) excise the fat pad for better exposure of the knee. There is still controversy about the result of fat pad excision on patella baja, pain, and function.

QUESTIONS/PURPOSES:

In the setting of a randomized controlled trial, we sought to determine whether infrapatellar fat pad excision during MIS TKA causes (1) patellar tendon shortening (as measured by patella baja); (2) increased anterior knee pain; (3) decreases in the Knee Society Score or functional subscore; or (4) more patella-related complications.

METHODS:

We randomized 90 patients undergoing MIS TKA at one institution into two groups. In one group, 45 patients underwent MIS TKA with complete infrapatellar fat pad excision and in the other group, 45 patients received MIS TKA without infrapatellar fat pad excision. The patella was selectively resurfaced in these patients; there was no difference between the groups in terms of the percentage of patients whose patellae were resurfaced. We measured patellar tendon shortening, knee flexion, anterior knee pain, Knee Society Score (KSS), functional subscore, and patellar complications at preoperative and postoperative periods of 6 weeks, 3 months, 6 months, and 1 year; complete followup data were available on 86% of patients (77 of 90) who were enrolled.

RESULTS:

At the final followup, no significant differences were observed in patellar tendon shortening, KSS, functional subscore, or knee flexion in either group. However, patients with their infrapatellar fat pad excised experienced more anterior knee pain (8.3% versus 0%; p = 0.03; 95% confidence interval, -0.007 to 0.174) at the end of the study. No patellar complications were found in either group.

CONCLUSIONS:

Infrapatellar fat pad excision in MIS TKA resulted in an increasing small percentage of patients with anterior knee pain after surgery. Surgeons should keep the fat pad if excellent exposure can be achieved but resect it if needed to improve exposure during TKA.

LEVEL I OF EVIDENCE:

 Pinsornsak P, Naratrikun K, Chumchuen S:The Effect of Infrapatellar Fat Pad Excision on Complications After Minimally Invasive TKA: A Randomized Controlled Trial. Clin Orthop Relat Res. 2013 Oct 18.