Date: April 16th, 2022

Reference: Blom et al. Common elective orthopaedic procedures and their clinical effectiveness: umbrella review of level 1 evidence. BMJ 2021

Guest Skeptic: Dr. Matt Schmitz, Pediatric Orthopedics, Adolescent Sports Medicine and Young Adult Hip Preservation Surgeon at San Antonio Military Medical Center in Texas.

Disclaimer: The views and opinions of this blog and podcast do not represent the United States Government or the US Military.

Case: A 55-year-old man comes into the emergency department (ED) for increasing knee pain and decrease in function. He’s had an anterior cruciate ligament (ACL) repair and used to run marathons. However, he is finding it more difficult to even put his socks on. Physical exam shows varus deformity at the knee, decreased range of motion, crepitus, no locking and neurovascularly intact distal. X-rays show severe, tri-compartment arthritis.

Background: Musculoskeletal complaints are one of the most common presentations to emergency departments. Often emergency physicians are assessing, treating, and answering patients question about orthopedic surgical procedures. How good is the evidence for the most common elective procedures?

Before we answer that question, let’s remind everyone that only a small number (2.8%) of interventions published in SRMA and relevant to emergency medicine have unbiased and strong evidence for improved outcomes (SGEM#361).

This is a broader problem in medicine. Tricoci et al. JAMA Feb 2009 looked at the ACC/AHA guidelines from 1984 to 2008. They found 53 guidelines with 7,196 recommendations. Only 11% of recommendations were considered Level A, 39% were Level B and 50% were Level C.

An update was published by Fanaroff et al in JAMA 2019. The level of high-quality evidence had not changed much when looking at the ACC/AHA guidelines from 2008-2018. There were 26 guidelines with 2,930 recommendations. Now Level A recommendations were down to 9%, Level B 50% and Level C 41%.

Time to turn our skeptical eye to the evidence for elective orthopaedic procedures.

Clinical Question: What is the effectiveness of common elective orthopaedic procedures compared with no treatment, placebo, or non-operative care?

Reference: Blom et al. Common elective orthopaedic procedures and their clinical effectiveness: umbrella review of level 1 evidence. BMJ 2021

  • Population: Meta-analyses of randomised controlled trials
    • Exclusions: Network meta-analyses (when pairwise meta-analyses were available), narrative reviews, systematic reviews that did not pool data or do a meta-analysis, and meeting abstracts
  • Intervention: Surgery
  • Comparison: No treatment, placebo, or non-operative care
  • Outcome: Quality and quantity of evidence behind the ten most common elective orthopaedic surgeries and comparisons with the strength of recommendations in relevant national clinical guidelines.

Authors’ Conclusions:Although they may be effective overall or in certain subgroups, no strong, high quality evidence base shows that many commonly performed elective orthopaedic procedures are more effective than non-operative alternatives. Despite the lack of strong evidence, some of these procedures are still recommended by national guidelines in certain situations.”

Quality Checklist for Therapeutic Systematic Reviews:

  1. The clinical question is sensible and answerable.  Yes/Unsure
  2. The search for studies was detailed and exhaustive. Yes
  3. The primary studies were of high methodological quality. Yes
  4. The assessment of studies were reproducible. Yes
  5. The outcomes were clinically relevant. Yes
  6. There was low statistical heterogeneity for the primary outcomes. Unsure
  7. The treatment effect was large enough and precise enough to be clinically significant. Yes, No and Unsure

Results: The ten most common elective orthopaedic procedures were identified using a literature search, an assessment of Hospital Episode Statistics procedure frequency counts, and discussions with expert orthopaedic surgeons.

Ten Most Common Elective Orthopaedic Procedures

  • arthroscopic anterior cruciate ligament reconstruction
  • arthroscopic meniscal repair of the knee
  • arthroscopic partial meniscectomy of the knee
  • arthroscopic rotator cuff repair
  • arthroscopic subacromial decompression
  • carpal tunnel decompression
  • lumbar spine decompression
  • lumbar spine fusion
  • total hip replacement
  • total knee replacement

Key Result: Only two out of ten common procedures, carpal tunnel decompression and total knee replacement, showed superiority over non-operative care.

They identified no RCTs that specifically compared total hip replacement or meniscal repair with non-operative care.

The six other common orthopaedic procedures showed no benefit over non-operative care.

1. Jadad Decision Algorithm: This is probably an unfamiliar process to most SGEM listeners. It is a process proposed in the late 1990’s to help decision-makers select from among discordant reviews [1]. Since its publication, the Jadad decisions algorithm is now commonly used to interpret between SRMA with discordant results [2,3].

2) Absence of Evidence: Just because we do not have high-quality RCTs does not mean we can conclude the procedures do not work. Total hip arthroplasty is one of the most successful surgical procedures in all of orthopedics.

3) Arthroscopic ACL Repair: The overall evidence does not support the routine reconstruction of a patients ACL. That does not mean a certain individual does not need their ACL repaired.

There as a landmark study called KANON (Knee Anterior cruciate ligament NON operative vs operative treatment) published over a decade ago (NEJM 2010).  KANON was an RCT of 121 young active adults with an acute ACL injury. The primary outcome was the change from baseline to two years in the average score on four subscales of the Knee Injury and Osteoarthritis Outcome Score (KOOS) and knee-related quality of life. They found that rehabilitation plus early ACL reconstruction was not superior to rehabilitation plus optional delayed ACL reconstruction.

A secondary analysis was just published that looked at the incidence of spontaneous healing of the ruptured ACL in the KANON trial (BMJ Sport and Ex Med 2022). They found there was a high rate of ACL healing in patients managed without surgery and only rehabilitation (56% at two years and 58% at five years). In addition, these individuals reported better patient-reported outcomes compared to the non-healed and reconstructed groups.

So, like most things in medicine the answer is it all depends. Decision to perform surgery depends on many factors including the patients’ values and preferences. What are their current activities, and do they want to continue those activities?

I had both my ACLs repaired well before the KANON trial. One repair went well while the other injured my common peroneal nerve, leaving me with foot drop for months and permanent decrease in sensation.

4) Possible Parachute: One of the other 10 common procedures lacking RCTs was arthroscopic meniscus repair. I don’t need an RCT to verify that it is not safe to jump out of an airplane without a parachute and I don’t need an RCT to inform my decision to repair a meniscus.

I would caution you that most medical procedures are not parachutes and an RCT could be conducted [4].  In fact, even parachutes were tested in a RCT, but the plane was on the ground and not moving (SGEM#284).

5) Potential Harms: We have been discussing the lack of superiority for efficacy in six out of ten common orthopedic procedures. It is important to also consider the potential harms. While modern surgery is very safe, there is increased morbidity and mortality with surgical interventions.

There is always a risk with surgical intervention.  Higher risks with things like joint arthroplasty or spine surgery so it is important to exhaust conservative measures.  However, when there is nerve impingement causing weakness (carpal tunnel, herniated disk, etc) delaying surgical decompression can lead to permanent weakness (different then neurogenic pain).

Comment on Authors’ Conclusion Compared to SGEM Conclusion: We generally agree with the authors’ conclusions.

SGEM Bottom Line: There is a lack of high-quality evidence to support all but two out of the ten most common elective orthopedic procedures.

Case Resolution: The patient with his progressively worse knee is referred to an orthopedic surgeon to discuss his options.

Clinical Application: This information can help patients and physicians in their decision-making process. In their supplemental material they compare their results to the American Academy of Orthopaedic Surgeons (AAOS) guidelines in Appendix 11.

AAOS clinical practice guidelines (CPGs) use similar methodology with work groups analyzing the best available evidence and grading it.  They look at not only surgical options but also non-surgical options (orthobiologics, steroids, physiotherapy for knee osteoarthritis, etc).  As is highlighted in this review, there is frequently a lack of high-level studies to support any intervention (operative or nonoperative) and that is reflected in the grading of CPG.

Dr. Matt Schmitz

What Does the Orthopedist Tell the Patient? I recommend exhausting all conservative measures before considering joint replacement surgery.  Although the technology is getting better (implants lasting longer), you will want to delay as long as possible because we know primary joint replacements have better outcomes than originals.  So, if you have it replaced, you only want it replaced once.  There is little downside to trying conservative management (therapy, injections, etc).

Keener Kontest:  Last weeks’ winner was Dr. Paeta Lehn from Vancouver Island. They new the hippocampus is typically affected on DW-MRI in transient global amnesia.

Listen to the podcast to hear this weeks’ question. Send your answer to with “keener” in the subject line. The first correct answer will receive a cool skeptical prize.

Remember to be skeptical of anything you learn, even if you heard it on the Skeptics Guide to Emergency Medicine.


  1. Jadad AR, Cook DJ, Browman GP. A guide to interpreting discordant systematic reviews. CMAJ 1997;156:1411-6.
  2. Ding F, Jia Z, Zhao Z, et al. Total disc replacement versus fusion for lumbar degenerative disc disease: a systematic review of overlapping meta-analyses. Eur Spine J 2017;26:806-15. doi:10.1007/s00586- 016-4714-y
  3. Zhao JG, Wang J, Long L. Surgical Versus Conservative Treatments for Displaced Midshaft Clavicular Fractures: A Systematic Review of Overlapping Meta-Analyses. Medicine (Baltimore) 2015;94:e1057. doi:10.1097/MD.0000000000001057
  4. Hayes MJ, Kaestner V, Mailankody S, Prasad V. Most medical practices are not parachutes: a citation analysis of practices felt by biomedical authors to be analogous to parachutes. CMAJ Open. 2018 Jan 15;6(1):E31-E38. doi: 10.9778/cmajo.20170088. PMID: 29343497; PMCID: PMC5878948.