Abstract
Background
Despite significant technological advancement in the field of shoulder arthroscopy, there remains limited evaluation of the evolution and categorization of shoulder arthroscopy patents. This bibliometric and patent analysis was performed to address this gap by systematically evaluating the most influential shoulder arthroscopy patents. The primary purpose of this study was to characterize the 100 most-cited shoulder arthroscopy patents by category of innovation and to analyze differences in citation metrics, including age-adjusted citation rates, and temporal trends across categories.
Methods
The Lens patent database was searched for patents containing “arthroscop∗” and “shoulder” in titles, abstracts, or claims, restricted to medical patents using Cooperative Patent Classification code A61. Patents were manually screened for relevance, ranked by forward citations, and the top 100 categorized into 6 groups: Arthroscopic Instruments, Fixation, Implants, Orthobiologic/Pharmacologic/Regenerative Medicine (OPR), Access and Retraction, and Computer-guided Systems. Non-parametric statistics compared forward citation counts and age-adjusted citation rates across categories. Significance was set at P < .05.
Results
Of 579 unique patents identified, 261 remained after screening. Among the top 100, median forward citation count was 97 (interquartile range: 26-188). Arthroscopic Instruments were most frequent (42%), followed by Fixation (19%), OPR (17%), Implants (15%), Access and Retraction (5%), and Computer-guided Systems (2%). Fixation patents had the highest median forward citation count (177, interquartile range: 92-308, P = .004) and highest median age-adjusted citation rate (8.40 citations/year, P = .002). Temporal analysis revealed a significant association between time period and category distribution (P = .005), with Arthroscopic Instruments decreasing from 82% in the ≤ 1995 period to 31% in 2006-2015, while Implants (0%-23%) and OPR (5%-23%) increased. At analysis, 46% of patents were expired, 41% active, and 13% inactive.
Conclusion
Arthroscopic Instruments and Fixation patents comprised more than half of the top 100 most-cited shoulder arthroscopy patents. Fixation patents demonstrated the highest citation impact, including the highest age-adjusted citation rate, a metric that showed no significant correlation with patent age and may therefore more reliably reflect technological influence independent of temporal bias. Age-adjusted citation rates and temporal trend analyses revealed a shifting patent landscape, with increasing innovation in Implants and OPR categories over time. This bibliometric and patent analysis characterizes the shoulder arthroscopy patent landscape and may serve as a resource for researchers, clinicians, and industry stakeholders seeking to identify areas of continued innovation.
Keywords: Shoulder arthroscopy, Patent analysis, Surgical innovations, Medical device patents, Suture anchors, Arthroscopic instruments, Fixation devices, Citation analysis
Shoulder arthroscopy has undergone significant advancements over the past 4 decades, transitioning from a primarily diagnostic tool to a comprehensive therapeutic approach for shoulder-related pathology.5 While knee arthroscopy gained widespread popularity in the 1970s, shoulder arthroscopy remained in its infancy until the early 1980s.8,17 However, subsequent innovation and developments in technology and surgical technique have led to shoulder arthroscopy becoming one of the most commonly performed orthopedic procedures, with more than 500,000 procedures performed annually in the United States alone.2,7 Key technological developments in the field of shoulder arthroscopy included the introduction of various portals for improved visualization, increasing use of the beach chair position, refinement of triangulation techniques, development of suture anchors and bioabsorbable tacks, and advances in electrosurgical and arthroscopic instrumentation.3,20
Despite extensive bibliometric analyses of clinical and surgical outcomes literature related to shoulder arthroscopy, patent analysis in this field remains limited.16,18 Patent databases provide a distinct resource for quantifying innovation in orthopedic surgery.14,15 Unlike scientific publications, patents are created with the objective of protecting intellectual property and securing commercial rights and often represent substantial financial investment and lengthy approval processes. Patent analysis therefore has the benefit of demonstrating how technology has evolved over time and allows for the discovery of possible unmet technological needs, such as gaps in surgical instrumentation, fixation techniques, or emerging areas where innovation has yet to match clinical demand.22 Prior patent bibliometric analyses in the field of orthopedic surgery have examined innovation in musculoskeletal medicine and minimally invasive spine surgery; however, no such analysis has been performed for shoulder arthroscopy.15,22 Given the rapid growth of shoulder arthroscopy and its associated technologies, a patent-focused bibliometric study may help identify patterns of innovation, highlight areas of concentrated technological development, and inform future research directions. This bibliometric and patent analysis was therefore designed to contribute to the growing body of literature by providing the first systematic evaluation of the shoulder arthroscopy patent landscape, with particular emphasis on age-adjusted citation rates as a metric to mitigate temporal bias in assessing technological influence.
The primary purpose of this study was to characterize the most-cited shoulder arthroscopy patents based on category of innovation, including Arthroscopic Instruments, Fixation, Implants, Orthobiologic/Pharmacologic/Regenerative Medicine (OPR), Access and Retraction, and Computer-guided Systems. The secondary purpose of this study was to analyze differences between categories with regard to citation metrics and describe temporal trends in the patent landscape. It was hypothesized that Arthroscopic Instruments would represent the most frequent category among the top 100 patents and that category of innovation would be associated with significant differences in forward citation metrics.
Materials and methods
A search of the Lens patent database was performed in October 2025 to identify patents related to shoulder arthroscopy. Lens is an open online platform that allows users to query and analyze patents and scholarly works, among other services.19 To date, Lens has compiled, cleaned, and aggregated more than 149 million patent records from sources worldwide, including the United States Patent and Trademark Office, the European Patent Office, PubMed, Open Researcher and Contributor ID, and CrossRef.19
The Lens patent database was searched for patent documents in the English language that: (1) contained the words “arthroscop∗” and “shoulder” in the title, abstract, or claim sections and (2) had a Cooperative Patent Classification code of A61 to restrict results to medical patents. Cooperative Patent Classification codes are a patent classification system developed in coordination between the United States Patent and Trademark Office and the European Patent Office and assign a hierarchical classification scheme to patents by section, class, subclass, and group. A61 refers to the “Human Necessities” section and the “Medical or Veterinary Science; Hygiene” class.
Patents were ordered by the number of forward citations, defined as the number of subsequent patents that have cited the indexed patent. Forward citations serve as a widely accepted proxy for technological influence, as patents that are frequently cited by subsequent patents have demonstrably shaped the direction of innovation in the respective field.6,15,22 Within the search results, duplicate patents resulting from reissued patents were identified using their priority date, date of publication, and application number. Forward citations of duplicates were summed and the entries condensed into a single patent record. Two independent reviewers (S.B. and V.M.) evaluated the title, abstract, and claims of each patent to ensure relevance to shoulder arthroscopy, removing patents primarily focused on other anatomical regions, with conflicts resolved by a third party (N.B.). The top 100 patents by forward citation count were selected for further detailed analysis (Fig. 1). This approach is consistent with prior patent bibliometric studies in orthopedic surgery and allows focus on the most influential patents, as measured by their downstream technological impact while maintaining analytical feasibility.15,22
Figure 1.
Patent identification and screening process. A total of 579 patents were identified from the Lens database search. After removal of duplicates and non-shoulder arthroscopy patents, 261 patents remained. The top 100 most-cited patents were selected for detailed bibliometric analysis and categorized by technology type. CPC, Cooperative Patent Classification.
The top 100 patents by forward citations were manually classified into 6 categories of shoulder arthroscopy technology by 2 independent reviewers (N.B. and V.M.) with an initial agreement rate of 90% (Cohen's κ = 0.87, indicating almost perfect agreement).9 Discrepancies were resolved by consensus with a third party (R.G.). The categories were defined as follows: (1) Arthroscopic Instruments, which included patents for surgical tools and devices such as forceps, suture passers, cannulated instruments, and electrosurgical tissue treatment systems; (2) Fixation, which included various suture anchors, bioabsorbable tacks, knotless fixation devices, and tissue attachment systems; (3) OPR, which included patents related to cartilage regeneration scaffolds, platelet-rich plasma applications, pharmaceutical agents for joint treatment, and other regenerative approaches; (4) Implants, which included artificial joint surfaces, prosthetic disks, and tissue repair implants designed specifically for shoulder applications; (5) Access and Retraction, which included arthroscopic retractors, cannula systems, clear view cannulae, and soft-tissue retraction devices; and (6) Computer-guided Systems, which included methods for computer-assisted surgery and intraoperative video analysis.
Citation metrics
The primary outcome measures were forward citation count and age-adjusted citation rate. To account for citation accrual over time, the age-adjusted citation rate was calculated as total forward citations divided by years since priority year, as of the date of analysis in 2026. Priority year represents the earliest filing date establishing patent rights and was used as the temporal denominator throughout this analysis.
To examine temporal trends in innovation, patents were divided into decade-based periods by priority year: ≤ 1995, 1996-2005, 2006-2015, and 2016 and later. The frequency of the 4 categories with more than 5 patents (Arthroscopic Instruments, Fixation, Implants, and OPR) within each period was evaluated; Access and Retraction (n = 5) and Computer-guided Systems (n = 2) were excluded from this analysis due to small sample sizes.
Legal status for each patent was recorded as reported by the Lens database and categorized as active, expired, or inactive (defined by Lens as patents that have lapsed or been withdrawn prior to expiration).
Statistical analysis
Descriptive statistics were reported as medians and interquartile ranges (IQRs) to reduce sensitivity to outliers in skewed citation distributions. Given the non-normal distribution of citation data (Shapiro-Wilk W = 0.740, P < .0001), non-parametric statistical tests were employed. The Kruskal-Wallis H test was used to compare forward citation counts and age-adjusted citation rates across the 6 patent categories, with post-hoc pairwise comparisons using the Mann-Whitney U test and Bonferroni correction for multiple comparisons. Effect sizes were calculated using rank-biserial correlation (r). Spearman correlation was then used to assess the relationship between priority year and citation metrics among all 100 patents pooled together, to evaluate whether citation accrual was influenced by patent age. Finally, chi-square tests evaluated associations between patent category and time period, and Fisher's exact test was used to confirm results when expected cell counts fell below 5.
Statistical analyses were performed using Python (version 3.11; Python Software Foundation) with the SciPy and pandas libraries. Statistical significance was set at P < .05.
Results
Search results and category distribution
From the initial search, 579 unique patents related to shoulder arthroscopy were identified and ordered by the number of forward citations. Duplicates (reissued patents) were identified and condensed, with forward citations combined, and non-shoulder arthroscopy patents were removed. After this initial screening, 261 patents remained (Fig. 1). The top 100 patents by forward citations were selected for further detailed analysis (Table I). Among the top 100 patents, the median forward citation count was 97 (IQR: 26-188, range: 3-1,052). The earliest priority year was 1977, and the 2000s decade demonstrated the highest patent count (44) of all included decades (Fig. 2).
Table I.
The top 100 most-cited shoulder arthroscopy patents.
| Rank | Priority year | Title | Citation count | Category |
|---|---|---|---|---|
| 1 | 1990 | Arthroscopic retractor and method of using the same | 1,052 | Access and Retraction |
| 2 | 1989 | Bioabsorbable tack for joining bodily tissue | 935 | Fixation |
| 3 | 1985 | Surgical instrument | 737 | Arthroscopic Instruments |
| 4 | 2008 | Implants for altering wear patterns of articular surfaces | 634 | Implants |
| 5 | 1999 | Bioabsorbable tissue tack with oval-shaped head and method of tissue fixation using the same | 486 | Fixation |
| 6 | 1993 | Surgical repair kit and its method of use | 457 | Arthroscopic Instruments |
| 7 | 1996 | Corkscrew suture anchor | 456 | Fixation |
| 8 | 2002 | Minimally invasive joint implant with 3-Dimensional geometry matching the articular surfaces | 442 | Implants |
| 9 | 2005 | Forceps for performing endoscopic or arthroscopic surgery | 436 | Arthroscopic Instruments |
| 10 | 2009 | Suture anchors with one way cinching mechanisms | 403 | Fixation |
| 11 | 2006 | Anti-extravasation sheath and method | 398 | Arthroscopic Instruments |
| 12 | 2015 | Tendon repair implant and method of implantation | 391 | Implants |
| 13 | 1998 | Resorbable scaffolds to promote cartilage regeneration | 341 | Implants |
| 14 | 1998 | Arthroscopic replacement of cartilage using flexible inflatable envelopes | 340 | Implants |
| 15 | 1985 | Method of arthroscopic repair of a limb joint | 333 | Arthroscopic Instruments |
| 16 | 2015 | Methods and systems for computer-aided surgery using intraoperative video acquired by a free moving camera | 322 | Computer-guided Systems |
| 17 | 2000 | Expandable tissue anchor | 321 | Fixation |
| 18 | 1992 | System and method for electrosurgical tissue contraction | 304 | Arthroscopic Instruments |
| 19 | 1989 | System and method of attaching bodily tissue to bone | 294 | Fixation |
| 20 | 1996 | Apparatus and methods for tendon or ligament repair | 271 | Fixation |
| 21 | 2005 | Looped high strength suture chain for knotless fixation | 255 | Fixation |
| 22 | 1987 | Fibrin clot delivery device and method | 244 | OPR |
| 23 | 2003 | Devices and methods used for shoulder replacement | 229 | Implants |
| 24 | 1997 | Systems and methods for electrosurgical tissue contraction | 222 | Arthroscopic Instruments |
| 25 | 1996 | Method for installing a threaded suture anchor with a cannulated suture anchor drill guide | 217 | Arthroscopic Instruments |
| 26 | 2006 | Clear view cannula | 188 | Arthroscopic Instruments |
| 27 | 2000 | Rotor blade anchor and tool for installing same particularly for arthroscopic installation | 188 | Fixation |
| 28 | 2017 | Device for the retraction of soft tissue in a patient undergoing arthroscopic surgery | 182 | Access and Retraction |
| 29 | 2006 | Cannulated suture anchor system | 177 | Fixation |
| 30 | 1999 | Method for controlling the chemical and heat induced responses of collagenous materials | 177 | OPR |
| 31 | 1995 | Systems and methods for electrosurgical tendon vascularization | 177 | Arthroscopic Instruments |
| 32 | 2006 | Arthroscopic harvesting and therapeutic application of bone marrow aspirate | 172 | OPR |
| 33 | 1992 | System for repair of bankart lesions | 168 | Arthroscopic Instruments |
| 34 | 1992 | System for repair of capsulo-labral separations | 166 | Arthroscopic Instruments |
| 35 | 1993 | Methods for electrosurgical tissue treatment between spaced apart electrodes | 157 | Arthroscopic Instruments |
| 36 | 1999 | Methods for attaching connective tissues to bone using a multicomponent anchor | 153 | Fixation |
| 37 | 2009 | Knotless suture anchor and methods of use | 141 | Fixation |
| 38 | 2009 | Bi-directional suture passer | 122 | Arthroscopic Instruments |
| 39 | 2000 | Methods for robotic arthroscopy | 117 | Computer-guided Systems |
| 40 | 1991 | Stabilization device and method for shoulder arthroscopy | 112 | Arthroscopic Instruments |
| 41 | 1977 | Operating arthroscope | 112 | Arthroscopic Instruments |
| 42 | 2008 | Medical apparatus and method for attaching a suture to a bone | 111 | Arthroscopic Instruments |
| 43 | 2003 | Cannulated instrument with curved shaft for passing suture through tissue | 110 | Arthroscopic Instruments |
| 44 | 2009 | Implantable tendon protection systems and related kits and methods | 109 | Implants |
| 45 | 2001 | Methods and compositions for improved articular surgery using collagen | 109 | OPR |
| 46 | 2007 | Dome shaped implant and inserter | 103 | Fixation |
| 47 | 2006 | Arthroscopic soft tissue plication systems and methods | 102 | Arthroscopic Instruments |
| 48 | 1989 | Inserter for engaging tissue to be oriented adjacent bone | 101 | Fixation |
| 49 | 1992 | System and method for electrosurgical cutting and ablation | 99 | Arthroscopic Instruments |
| 50 | 1983 | Arthroscopic surgical instrument and method | 98 | Arthroscopic Instruments |
| 51 | 2009 | Surgical retention port and method of use | 96 | Access and Retraction |
| 52 | 2000 | Notched suture hook | 94 | Arthroscopic Instruments |
| 53 | 2010 | Method and devices for implantation of biologic constructs | 88 | Implants |
| 54 | 1995 | Working cannula for arthroscopy | 85 | Arthroscopic Instruments |
| 55 | 2014 | Methods of orienting multifilament yarn and monofilaments of poly-4-hydroxybutyrate and copolymers thereof | 83 | Fixation |
| 56 | 2006 | Arthroscopic bone transplanting procedure, and medical instruments useful therein | 83 | Arthroscopic Instruments |
| 57 | 1995 | Shoulder arthroscopy attachment | 82 | Arthroscopic Instruments |
| 58 | 1993 | Methods for tissue ablation using pulsed energy | 73 | Arthroscopic Instruments |
| 59 | 2004 | Method and apparatus for arthroscopic joint resurfacing | 68 | Fixation |
| 60 | 2011 | Subchondral treatment to prevent the progression of osteoarthritis of the joint | 65 | Arthroscopic Instruments |
| 61 | 1998 | Systems and methods for electrosurgical tendon vascularization | 60 | Arthroscopic Instruments |
| 62 | 2011 | Arthroscopic total shoulder arthroplasty | 59 | Implants |
| 63 | 2005 | Method and apparatus for providing a passageway | 53 | Access and Retraction |
| 64 | 2015 | Suture sleeve patch and methods of delivery within an existing arthroscopic workflow | 52 | Implants |
| 65 | 2001 | Holding device for wrist/shoulder arthroscopy and surgery | 49 | Arthroscopic Instruments |
| 66 | 2013 | Compositions and methods for pain relief without numbness | 48 | OPR |
| 67 | 2001 | Surgical shoulder drape with pouch | 48 | Arthroscopic Instruments |
| 68 | 2011 | Methods and apparatus for delivering and positioning sheet-like materials in surgery | 44 | Arthroscopic Instruments |
| 69 | 2015 | Arthroscopic surgical device | 41 | Arthroscopic Instruments |
| 70 | 2011 | System and method for treating soft tissue with force impulse and electrical stimulation | 40 | Arthroscopic Instruments |
| 71 | 2003 | Method of minimally invasive shoulder replacement surgery | 39 | Implants |
| 72 | 2000 | Arm suspension sleeve | 33 | Arthroscopic Instruments |
| 73 | 2015 | Measuring tool using suture and suture anchor | 31 | Arthroscopic Instruments |
| 74 | 2003 | System and method for salivary stones removal and joint arthroscopy | 30 | Arthroscopic Instruments |
| 75 | 2008 | Instillation administration of capsaicinoids for the treatment of pain | 29 | OPR |
| 76 | 2006 | Method for tissue fixation | 26 | Fixation |
| 77 | 1985 | Arm suspension mitt | 25 | Arthroscopic Instruments |
| 78 | 1989 | Shoulder arthroscopy abduction apparatus | 22 | Arthroscopic Instruments |
| 79 | 1987 | Acromioplasty guide pins | 21 | Arthroscopic Instruments |
| 80 | 2004 | Amorphous cell delivery vehicle treated with physical/physicochemical stimuli | 20 | OPR |
| 81 | 2003 | Method of arthroscopic or open rotator cuff repair using an insertional guide for delivering a suture pin | 19 | Arthroscopic Instruments |
| 82 | 2007 | Methods for implanting a prosthesis in a human shoulder | 18 | Implants |
| 83 | 1997 | Coupling for sealing and connecting 2 elongate medical instruments | 17 | Arthroscopic Instruments |
| 84 | 2012 | Knotless filament anchor for soft tissue repair | 16 | Fixation |
| 85 | 2002 | Shoulder arthroscopy chair | 16 | Arthroscopic Instruments |
| 86 | 2007 | Composition for treatment of cartilage disease | 15 | OPR |
| 87 | 2015 | A method for morselizing and/or targeting pharmaceutically active principles to synovial tissue | 14 | OPR |
| 88 | 2004 | Use of a vanilloid receptor agonist together with a glycosaminoglycan or proteoglycan for producing an agent for treating articular pains and method for applying said agent | 14 | OPR |
| 89 | 2017 | Method, compositions and articles for improving joint lubrication | 13 | OPR |
| 90 | 2004 | Synovial villi for use with tissue engineering | 13 | OPR |
| 91 | 2004 | Use of resiniferatoxin (RTX) for the preparation of an agent for the treatment of pain | 12 | OPR |
| 92 | 2007 | Methods of arthroscopic osteochondral resurfacing | 11 | OPR |
| 93 | 2012 | Method of humeral head resurfacing and/or replacement and system for accomplishing the method | 10 | Implants |
| 94 | 2003 | Tissue grasping instrument and method for use in arthroscopic surgery | 10 | Access and Retraction |
| 95 | 2007 | Method of arthroscopic osteochondral resurfacing using PRP strengthened with fibrin glue | 9 | OPR |
| 96 | 1996 | Use of fluorocarbons for diagnosis and treatment of articular disorders | 9 | OPR |
| 97 | 2015 | Suture sleeve patch and methods of delivery within an existing arthroscopic workflow | 8 | Fixation |
| 98 | 2018 | Arthroscopic shoulder arthroplasty and method thereof | 6 | Implants |
| 99 | 2012 | Implantation of micronized allograft tissue over a microfractured defect | 5 | OPR |
| 100 | 2020 | Implants and methods for shoulder joint reconstruction | 3 | Implants |
OPR, Orthobiologic/Pharmacologic/Regenerative Medicine.
Patents are ranked by forward citation count. Priority year represents the earliest filing date. Categories include Arthroscopic Instruments, Fixation, Implants, Orthobiologic/Pharmacologic/Regenerative Medicine (OPR), Access and Retraction, and Computer-guided Systems.
Figure 2.
Distribution of the top 100 most-cited shoulder arthroscopy patents by priority year decade. The 2000s decade had the highest number of patents (n = 44, highlighted in orange), followed by the 1990s (n = 24) and 2010s (n = 20). The earliest patent had a priority year of 1977.
The top 100 patents were categorized as follows: 42 (42%) were classified in the Arthroscopic Instruments category, 19 (19%) in Fixation, 17 (17%) in OPR, 15 (15%) in Implants, 5 (5%) in Access and Retraction, and 2 (2%) in Computer-guided Systems.
Forward citation analysis
Forward citation metrics varied significantly by category (Kruskal-Wallis H = 17.08, P = .004) (Fig. 3). Among categories with more than 5 patents, Fixation patents exhibited the highest median citation count (median: 177, IQR: 92-308, n = 19), followed by Arthroscopic Instruments (median: 96, IQR: 42-168, n = 42), Implants (median: 88, IQR: 29-341, n = 15), and OPR (median: 14, IQR: 12-48, n = 17). Access and Retraction had a median citation count of 96 (IQR: 53-182, n = 5) and Computer-guided Systems had a median citation count of 220 (IQR: 168-271, n = 2), although notably with sample size of 5 or less patents. Post-hoc pairwise comparisons with Bonferroni correction revealed that Fixation patents had significantly higher citation counts than OPR patents (U = 278.0, P < .001, r = 0.72).
Figure 3.
Distribution of forward citation counts by patent category among the top 100 cited shoulder arthroscopy patents. Box plots display median (horizontal line), interquartile range (box), and range (whiskers); outliers are shown as individual points. Computer-guided Systems (n = 2) and Access & Retraction (n = 5) are displayed for completeness but should be interpreted with caution due to small sample sizes. Categories are ordered by descending median forward citation count. OPR, Orthobiologic/Pharmacologic/Regenerative Medicine.
Age-adjusted citation rates
Age-adjusted citation rates also differed significantly across categories (Kruskal-Wallis H = 19.29, P = .002) (Fig. 4). Fixation patents exhibited the highest median age-adjusted citation rate among categories with more than 5 patents (median 8.40 citations/year), followed by Implants (median 6.29 citations/year), Access and Retraction (median 6.40 citations/year), Arthroscopic Instruments (median 3.92 citations/year), and OPR (median 1.00 citation/year). Computer-guided Systems had a median of 20.33 citations/year (n = 2). Pairwise comparisons identified that Fixation patents (P < .001, r = 0.72, large effect) and Implants (P = .005, r = 0.58, large effect) had significantly higher age-adjusted citation rates than OPR patents. Raw forward citations showed a significant negative correlation with priority year (Spearman ρ = −0.371, P < .001), confirming the time-dependent nature of citation accrual. In contrast, the age-adjusted citation rate showed no significant correlation with priority year (Spearman ρ = −0.058, P = .567), suggesting that this metric mitigates temporal bias in citation accumulation.
Figure 4.
Age-adjusted citation rates by patent category among the top 100 cited shoulder arthroscopy patents. Box plots display median (horizontal line), interquartile range (box), and range (whiskers); outliers are shown as individual points. Age-adjusted citation rate was calculated as total forward citations divided by years since priority date. Computer-guided Systems (n = 2) and Access & Retraction (n = 5) are displayed for completeness but should be interpreted with caution due to small sample sizes. OPR, Orthobiologic/Pharmacologic/Regenerative Medicine.
Temporal trends
Temporal analysis by decade among the 4 categories with more than 5 patents revealed a significant association between time period and category distribution (χ2 = 23.55, df = 9, P = .005; confirmed by Fisher's exact test, P = .003). Arthroscopic Instruments was the most frequent category in the earliest time period (82% of patents in the ≤ 1995 period) but decreased in frequency over time (31% in 2006-2015), while Implants increased from 0% to 23% and OPR from 5% to 23% over the same periods (Fig. 5).
Figure 5.
Distribution of patent categories by priority year era among the top 100 cited shoulder arthroscopy patents. Stacked bar chart showing the percentage of patents within each decade-based era classified into the 4 categories with more than 5 patents: Arthroscopic Instruments, Fixation, Implants, and Orthobiologic/Pharmacologic/Regenerative Medicine. Access and Retraction (n = 5) and Computer-guided Systems (n = 2) were excluded due to small sample sizes. OPR, Orthobiologic/Pharmacologic/Regenerative Medicine.
Legal status
At the time of analysis, among the top 100 patents, 46 (46%) were expired, 41 (41%) were active, and 13 (13%) were inactive. Median citations were higher among expired patents (135, IQR: 54.75-288.25) than active (68, IQR: 19-172) or inactive patents (30, IQR: 14-99).
Discussion
The predominance of Arthroscopic Instruments in the top 100 patents (42%) reflects the fundamental importance of visualization and tool development in advancing shoulder arthroscopy. The shoulder joint presents unique challenges compared to other joints, including a thick soft tissue envelope, which may complicate direct palpation of the glenohumeral joint space, proximity of 6 major nerves and vessels to standard portal sites, and significant variation in normal anatomy.8,17 These anatomical constraints necessitated instruments specifically designed for the shoulder, which may explain the high volume of patented innovations in this category. Notably, the single most-cited patent in the entire dataset was an arthroscopic retractor (1990, 1,052 citations), categorized under Access and Retraction, underscoring the importance of adequate visualization and tissue management in shoulder arthroscopy. Within the Arthroscopic Instruments category, the most-cited patent was a motorized rotary tissue resector (1985, 737 citations), while other highly cited patents included forceps for endoscopic surgery (2005, 436 citations), an electrosurgical tissue contraction system (1992, 304 citations), and cannulated instruments for passing sutures through tissue (2003, 110 citations). The significant association between time period and category distribution revealed that Arthroscopic Instruments accounted for the majority of early patents (82% in the ≤ 1995 period) but decreased in frequency over time as the field diversified, with Implants and OPR categories conversely showing substantial growth.
A second key finding was that Fixation patents, while representing only 19% of the top 100 patents, exhibited the highest median citation count (177) and age-adjusted citation rate (8.40 citations/year), with statistically significant differences in citation metrics across all categories and significantly higher citation counts compared to OPR patents specifically. Notable Fixation patents included the bioabsorbable tack for tissue fixation (1989, 935 citations), the corkscrew suture anchor (1996, 456 citations), and various knotless suture anchor systems. These innovations have substantially transformed arthroscopic shoulder stabilization, with arthroscopic Bankart repair now widely regarded as the standard operative treatment for traumatic anterior shoulder instability.4,11 Studies have consistently demonstrated that adequate suture anchor placement, typically using 3 or more anchors, is critical for successful arthroscopic Bankart repair outcomes and lower recurrent instability rates.1,21 The significantly lower citation rates in the OPR category compared to Fixation and Implants categories may be attributed to the more recent emergence of orthobiologic technologies and their ongoing clinical validation rather than intrinsically lower innovation value among OPR patents.
The analysis of temporal trends and age-adjusted metrics provided insight into the evolving landscape of shoulder arthroscopy innovation. The finding that expired patents had higher citation counts than active or inactive patents reflects the time-dependent nature of citation accrual rather than intrinsic superiority. The significant negative correlation between priority year and raw forward citations confirms this temporal bias. Importantly, the age-adjusted citation rate showed no such correlation, validating this metric as an appropriate measure of citation impact independent of patent age.22 Computer-guided Systems, while representing only 2% of the top 100 patents, exhibited the highest median age-adjusted citation rate, which may reflect the rapidly growing interest in computer-assisted orthopedic surgery and artificial intelligence applications in the field.10,13 The relatively small number of patents in this category within the top 100 may reflect the more recent emergence of these technologies, indicating potential opportunity for future innovation.
The temporal shift in patent activity from Arthroscopic Instruments toward Fixation, Implants, and OPR categories is consistent with the broader clinical evolution of shoulder arthroscopy from a primarily diagnostic and débridement-focused modality to one centered on complex reconstructive and biologic interventions.5 As arthroscopic techniques for rotator cuff repair, labral reconstruction, and superior capsular reconstruction have become increasingly prevalent, the patent landscape has correspondingly reflected growing emphasis on anchoring systems, implant design, and regenerative approaches.12 Furthermore, the under-representation of Computer-guided Systems among highly cited patents (2%), despite increasing clinical adoption of surgical navigation and artificial intelligence, may signal an area where technological innovation has not yet matched clinical demand.10,13
Recognizing how the technological landscape of shoulder arthroscopy has evolved is important for inspiring new innovations that build on prior advances. Bibliometric analyses focused solely on scientific research likely miss the technological advances made in the patent space. Furthermore, patents represent different goals than scientific literature, often reflecting substantial financial investment and lengthy development and approval processes.14,15 Therefore, understanding the patent landscape may help providers and inventors identify unmet technological needs and position new innovations strategically. The present study contributes to the growing body of literature by providing the first bibliometric and patent analysis focused specifically on shoulder arthroscopy. In particular, the age-adjusted citation rate findings reported herein may offer a more reliable framework for evaluating patent influence than raw citation counts alone, as this metric was shown to be independent of patent age and may therefore better guide researchers and innovators in identifying areas of continued technological need.
Limitations
This study was subject to several limitations. First, the categorization of patents was subjective and prone to potential bias. Second, the search criteria did not search the entire text of each patent, potentially missing some relevant shoulder arthroscopy patents. Third, forward citation counts may be influenced by factors other than technological impact, including commercial success and patent portfolio strategies, and thus should be interpreted as one measure of influence rather than a definitive indicator of clinical significance. Fourth, small sample sizes in certain categories (Computer-guided Systems, n = 2; Access and Retraction, n = 5) limit statistical power and generalizability for these groups. Fifth, the focus on the top 100 patents introduces survival bias, as highly cited patents may not represent the full spectrum of innovation. Finally, the Lens database, while comprehensive, may not capture all global patent activity.
Conclusion
Shoulder arthroscopy patents related to Arthroscopic Instruments and Fixation accounted for more than half of the top 100 most-cited patents. Fixation patents demonstrated the highest citation impact as measured by both forward citation counts and age-adjusted citation rates, the latter of which was shown to mitigate temporal bias and may therefore more reliably reflect technological influence. Temporal trends demonstrated a significant shift from early instrumentation-focused innovation toward increasing patent activity in Implants and OPR categories. This bibliometric and patent analysis provides a systematic characterization of the shoulder arthroscopy patent landscape and may serve as a foundation for researchers, clinicians, and industry stakeholders to identify areas of continued innovation in the field.
Disclaimers:
Funding: No funding was disclosed by the authors.
Conflicts of interest: Albert Lin reports that he serves in fiduciary officer roles for ISAKOS, restor3d, Inc., the American Shoulder and Elbow Surgeons (ASES), the Arthroscopy Journal, Annals in Joint, the Rotator Cuff Study Group, JBJS Case Connector, and the Arthroscopy Association of North America. He performs other professional activities for Arthrex, restor3d, Inc., and Stryker and holds other intellectual property. He serves on multiple boards and committees, including the Board of Directors for the Rotator Cuff Study Group, the Research and Shoulder Committee of ISAKOS, and as Co-Chair of the Education Committee for ASES. He also serves on editorial or governing boards, including the Editorial Board of the Arthroscopy Journal, as Associate Editor for JBJS Case Connector, and as Editor-in-Chief of Annals in Joint.
Any additional authors, their immediate families, and any research foundations with which they are affiliated have not received any financial payments or other benefits from any commercial entity related to the subject of this article.
Footnotes
This study involved the analysis of publicly available patent data and did not involve human subjects research. Institutional review board approval was not required.
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