Learning curves in arthroscopic surgery: A scoping review of knee, shoulder, and hip procedures

Study design and framework

This scoping review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology. A detailed search and screening strategy was developed to identify peer-reviewed studies reporting learning curve metrics for knee, hip, or shoulder arthroscopy.

Information sources and search strategy

Databases searched: PubMed/MEDLINE, Embase

Search terms included “Arthroscopy,” “Learning Curve,” “Knee,” “Shoulder,” “Hip,” “Surgical education,” “Experience,’’ and “Tertiary care center.”

Eligibility criteria

Inclusion criteria were (1) original clinical studies involving knee, hip, or shoulder arthroscopic procedures; (2) studies reporting measurable learning curve outcomes (e.g., operative time, complication rate); (3) comparisons of surgeon experience (novice vs. experienced); and (4) publication in peer-reviewed journals within the past 25 years. Exclusion criteria included simulation-only studies without clinical outcome data, non–peer-reviewed reports, and studies focused on unrelated surgical domains.

Exclusion

• (1) Simulation-only studies without clinical outcomes;

• (2) Cadaveric-only studies;

• (3) non-arthroscopic procedures;

• (4) Reviews, editorials, case reports.

A total of 1800 records were identified. After duplicate removal and screening, 20 studies were included:

• Knee arthroscopy: 6

• Shoulder arthroscopy: 7

• Hip arthroscopy: 7.

PRISMA Framework

The Study Selection process conducted in accordance with PRISMA guidlines, including identification, screening, eligibility and inclusion stages as illustated in flow diagram [Figure 1].

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Figure 1:

PRISMA framework.

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Operational definitions

To allow synthesis across studies, surgeon experience categories were defined based on common cutoffs in the literature:

• Novice/early experience: Surgeons who have performed fewer than 30 arthroscopic procedures for a given joint

• Experienced: Surgeons who have performed ≥30 procedures

• The 30-case threshold was selected as a pragmatic comparative reference point based on frequently cited early learning curve cutoffs in arthroscopic literature. However, this threshold does not represent definitive procedural mastery. True proficiency thresholds vary by joint and procedure, with hip arthroscopy often requiring substantially higher case volumes.

Study characteristics

Table 1 summarizes the included studies by author, year, joint, sample size, primary learning metric, and identified proficiency threshold. We included both clinical and simulation-based studies. Evidence for knee arthroscopy learning curves was predominantly derived from simulator-based and training-focused studies, whereas shoulder and hip arthroscopy conclusions were primarily based on clinical outcome investigations. Designs varied: Several were prospective series (e.g. Hodgins et al. 2014, Guttmann et al. 2005, You et al. 2020, Haipeng et al. 2021), ^[3,5-7] while others were retrospective analyses (e.g. Elkins et al. 2020, Dumont et al. 2020, Westermann, 2023). ^[8-10] Most were single-surgeon series or small cohorts, except Hodgins et al. ^[3] (multiple trainees) and Go et al. ^[11] (systematic review of 13 hip studies).

Joint-specific outcomes, risks, and case thresholds

Table 2 summarizes common complications, risk factors, and approximate case thresholds by joint. These entries combine findings from the above studies and established literature.

Knee arthroscopy

Direct clinical comparisons of knee arthroscopy outcomes between novice and experienced groups are scarce. However, training studies show improved technical performance with repetition. Residents generally show faster task completion and fewer unintentional camera movements than novices, indicating skill acquisition that may translate to better clinical performance. While specific clinical operative time differences are not well-quantified by a set case threshold, simulator-based assessments consistently demonstrate that operative efficiency improves with repetition.^[12]

Shoulder arthroscopy

For arthroscopic RCR, clinical outcomes improve with increasing surgeon experience. In a study comparing the first 100 consecutive cases to a later set of 100 cases, retear rates decreased from ~18% to ~8% as experience increased.^[13] Operative times also decline; in one large analysis, mean operative time decreased from ~35 min in early cases to ~20 min after substantial experience.^[8] General complication rates for shoulder arthroscopy are approximately 7.9%, with stiffness and residual pain being most common.^[14]

Hip arthroscopy

Hip arthroscopy exhibited the steepest learning curve. Prospective evaluations indicate significant reductions in procedure and traction times after approximately 70–110 cases, with maximum efficiency often achieved past this threshold.^[7] A systematic review also showed that the quality of outcomes improved significantly after approximately 250 cases, with PROs continuing to improve beyond even larger case volumes, suggesting that extended experience enhances final clinical results.^[9] A study comparing three sequential groups of cases found that the initial 75 procedures required significantly longer surgical times than later cases, reflecting operative efficiency improvements as surgeons progress along the learning curve.^[10] In addition, studies report that surgeons performing >25 hip arthroscopies per year had shorter idle/operative components than lower-volume surgeons, reinforcing that increasing procedural volume correlates with greater efficiency.^[15] Hip arthroscopy complication rates decrease as surgeons gain experience. A systematic review of studies on learning curves found that measures such as complication rates and reoperation rates reduced with increasing surgeon experience. Specifically, complication rates ranged widely among early cases but trended downward in later cases, with some studies noting reductions from higher early percentages to lower rates with accumulated experience.^[11]

Clinical outcomes and surgeon experience

Arthroscopic RCR, a common shoulder procedure, demonstrates improved clinical outcomes with increasing surgeon experience. In a study comparing the first 100 consecutive cases to a later set of 100 cases performed by the same surgeon, retear rates decreased from ~18% to ~8% as experience increased, demonstrating improved structural outcomes with experience.^[13] One systematic analysis suggested that functional outcomes improved after around 250 cases of hip arthroscopy, indicating that clinical improvement may extend beyond initial procedural efficiency gains.^[2]

Operative time trends

Knee arthroscopy simulation studies also support improvements in task performance time with repeated practice, although robust clinical series documenting operative time differences stratified by case experience remain limited. Simulation evidence shows that trainees achieve reduced task completion time with repetition.^[16] For hip arthroscopy, operative and traction times have been reported to decrease with increasing surgeon experience. Systematic reviews frequently use 30 cases as a pragmatic threshold differentiating early from late experience, with significant operative time reductions noted beyond this point.^[2] In shoulder arthroscopy, large cohort studies show that operative times decline progressively with experience, with early case series having longer mean surgical times that steadily reduce as surgical proficiency increases. Although specific numeric values differ by study, the general trend is consistent.^[17] In one large analysis, the mean operative time decreased over a series of 1,600 arthroscopic repairs, with early cases averaging around 35 min and later cases ~20 min after substantial experience. This suggests a progressive learning curve in operative efficiency as cumulative experience increases.^[8]

Complication rate and safety outcomes

For knee arthroscopy, detailed published data on experience-specific complication rates are limited, but improved technical skill in simulator and training contexts likely correlates with fewer procedural misadventures and improved intraoperative judgment.^[17] In shoulder arthroscopy, complications such as stiffness or residual pain tend to become less frequent with increasing surgeon experience.^[14] Hip arthroscopy learning curve studies indicate that portal-related complications are more frequent among early cases and decline with experience, reflecting improved technique and familiarity with complex three-dimensional anatomy. Surgeons with higher cumulative experience achieve better tissue handling, reduced inadvertent damage, and fewer technical errors.^[2]

Learning progression in arthroscopy may be conceptualized hierarchically. Initial improvements are typically observed in technical efficiency, reflected by reductions in operative time. This is followed by enhanced procedural safety, demonstrated by decreasing complication and reoperation rates. Structural success metrics, such as tendon integrity or labral preservation, improve thereafter, while optimization of patient-reported outcomes represents the most advanced stage of surgical proficiency. Therefore, operative time alone should not be equated with true surgical mastery.

Advantages of the tertiary care center for the new surgeon

Disadvantages

Future strategies to flatten the learning curve in tertiary care centers

Tertiary care centers play a key role in musculoskeletal training, patient volume, and specialized surgical education. To support early arthroscopy surgeons and reduce the steepness of learning curves (especially for hip, knee, and shoulder arthroscopy), the literature suggests several effective strategies – both educational and structural that can be adopted and optimized within tertiary care settings.

Structured simulation-based training

Simulation courses provide trainees with safe opportunities to practice arthroscopic skills without patient risk. These are especially valuable in tertiary centers where simulation laboratories and educator resources are available. This improves baseline proficiency before real surgical cases. Simulator-based instruction is supported by orthopedic training programs as a means to enhance visual-spatial skills, anatomic recognition, and operative efficiency, all of which contribute to flattening early learning curves.^[22]

Cadaveric and procedural laboratories integrated with clinical mentorship

Cadaveric laboratories offer a bridge between simulation and actual surgery by allowing trainees to perform steps of procedures in realistic anatomic environments. With direct supervision from subspecialist faculty, trainees benefit from real-time guidance and iterative practice of surgical steps – a powerful component of flattening the learning curve in complex arthroscopic procedures.^[23]

Objective performance monitoring and feedback

Using validated objective measures such as motion-tracking or structured assessment tools gives trainees actionable feedback which is essential for deliberate practice. In tertiary care settings, integrating skill tracking into the curriculum ensures trainees receive individualized feedback and can adjust their training based on measurable performance indicators. Examples include standardized performance scores or simulator-generated metrics that reflect efficiency and precision beyond simple case counts.^[24]

Mentorship-focused case supervision

The presence of senior, experienced surgeons actively mentoring junior surgeons in the operating room has been shown to flatten learning curves dramatically. In studies of robotic-assisted knee arthroplasty, surgical teams working with an experienced surgeon demonstrated significantly faster improvements in operative times compared with teams without consistent expert assistance, highlighting the value of mentorship. This “co-teaching” or mentorship pairing model can be particularly impactful in tertiary care centers, where expert faculty can supervise initial procedures, reducing early errors and promoting safe progression.^[25]