Proximal Interphalangeal Joint Arthrodesis: What the Research Says

Evidence from 20 peer-reviewed studies

8 Case Report
12 Expert Opinion

What Professionals Should Know

  • This 3D-printed aiming device is particularly valuable for less experienced surgeons performing PIPJ arthrodesis, significantly reducing operative time and radiation exposure while improving screw placement accuracy
  • The device may reduce the learning curve for PIPJ arthrodesis, making this technically demanding procedure more accessible to developing surgical skills
  • Experienced surgeons achieved optimal results with freehand technique, suggesting the device's greatest benefit is in supporting competency development rather than improving gold-standard outcomes
  • Request preoperative CT for comminuted middle phalanx fractures in Warmbloods—it reveals fracture patterns and concurrent injuries that radiographs miss, directly improving your surgical planning and implant positioning
  • Be aware that these cases often have hidden injuries (navicular involvement, tendon rupture) that CT can identify before surgery, potentially changing your approach
  • Expect mild lameness (3/5) as a realistic long-term outcome even with optimal surgical planning; discuss this prognosis honestly with owners
  • When OCLLs occur on the convex surface of the proximal phalanx where conservative drilling/screw placement is technically difficult, joint arthrodesis combined with biocement filling may be a viable surgical option
  • This approach may be particularly suitable for young horses with significant lameness from large, clinically relevant phalangeal cysts
  • Three-screw arthrodesis technique (two paraxial, one axial crossed lag screw) provides stable fixation for this procedure
  • The PIP-LCP offers a surgical option for treating PIPJ arthritis when conservative management fails, with comparable outcomes to other arthrodesis techniques
  • This technique combines plate and screw fixation, potentially providing enhanced stability for pastern joint fusion
  • Veterinary surgeons considering PIPJ arthrodesis should familiarize themselves with this method as an alternative to traditional approaches
  • PIP arthrodesis is a viable treatment for osteoarthritis in sport horses across multiple disciplines, with success rates exceeding 74% for return to intended use
  • Horses undergoing hindlimb PIP arthrodesis have substantially better athletic performance outcomes than those with forelimb procedures—consider this when counseling clients on prognosis
  • Multiple fixation techniques (3-screw, DCP, LCP) appear effective, allowing surgeon and owner flexibility based on available resources and anatomical considerations
  • Intra-articular ethyl alcohol injection alone is not a reliable method for achieving PIP joint arthrodesis in clinical practice
  • Even when combined with transarticular screws and immobilization, this technique produced fusion in only 1 of 6 joints, making it unsuitable for routine use
  • Practitioners should continue using established arthrodesis methods rather than relying on this minimally invasive ethyl alcohol approach
  • LCP is a viable surgical option for complex fractures and arthrodeses in horses when rigid fixation is needed for early post-operative comfort
  • Expect infection-related complications in approximately one-third of cases; careful post-operative management and monitoring are essential
  • Monitor for systemic complications including contralateral limb laminitis and colic, which collectively occurred in 22% of cases
  • Two parallel 5.5 mm cortical screws are sufficient for PIP joint arthrodesis—using three offers no mechanical advantage and increases surgical time and cost
  • Either configuration can be expected to tolerate normal bending forces under similar loading conditions
  • Simpler surgical technique with two screws reduces anesthetic time and soft tissue trauma without compromising construct strength
  • The locking compression-distal femur plate effectively stabilizes the joint and prevents proximal interphalangeal subluxation in horses with severe suspensory apparatus damage, offering a surgical option when conservative management fails
  • Expect significant postoperative complications—over three-quarters of horses develop issues like support limb laminitis or infection—requiring intensive perioperative care and realistic owner counseling about survival rates (~50% long-term)
  • For working racehorses, this procedure offers a pathway to pasture soundness without chronic medication for roughly half of survivors, but should be reserved for cases at imminent risk of catastrophic joint failure rather than as a routine salvage procedure
  • Both open and closed techniques for PIP arthrodesis perform equally well mechanically, so surgical choice can be based on surgeon preference and case-specific factors
  • LC-DCP and LCP plates show equivalent mechanical performance, allowing clinicians to select based on availability, cost, or surgeon familiarity
  • These findings support the clinical use of either implant combination, but longer-term clinical studies are needed to validate biomechanical findings in live horses
  • For equine PIP joint arthrodesis procedures, locking compression plates offer greater load-bearing capacity and structural rigidity than dynamic compression plates in laboratory conditions
  • Both plate types show similar displacement characteristics, suggesting comparable functional outcomes in early post-operative loading phases
  • Clinical outcomes should be validated as this is cadaveric testing; biomechanical superiority of LCP may translate to faster healing and earlier return to function in live horses
  • The locking compression plate (PIP-LCP) provides superior stability with less micromotion during cyclic loading, which may reduce complications and promote faster arthrodesis healing compared to the LC-DCP
  • Both plate types demonstrate equivalent ultimate strength, so plate selection can be guided by the superior stiffness of the PIP-LCP and its resistance to micromotion
  • Failure occurs at the transarticular screws regardless of plate type, suggesting screw integrity and positioning warrant careful attention in clinical application
  • Both fixation techniques combine an axial plate with abaxial screws; understanding the biomechanical differences helps surgeons select the most appropriate method for individual cases
  • The choice between locking and dynamic compression plates for PIP arthrodesis should consider the specific biomechanical properties demonstrated in this in vitro comparison
  • Either the locking compression plate or dynamic compression plate can be selected for equine PIP arthrodesis based on surgeon preference and availability, as biomechanical performance is equivalent
  • Both plate types maintained construct stability through 20,000 loading cycles, suggesting either is suitable for supporting early mobilization in clinical cases
  • When combined with two transarticular cortex screws, both 3-hole 4.5 mm plate designs provide comparable resistance to gap formation and rotation
  • For PIP joint arthrodesis procedures, traditional AO 5.5 mm cortical screws in lag fashion provide superior construct stability and fatigue resistance compared to Acutrak Plus headless screws
  • Consider AO cortical screw technique as the preferred method for PIP arthrodesis when biomechanical stability is the priority
  • This in vitro data supports continued use of established AO lag screw fixation rather than switching to newer headless screw designs for this procedure
  • This in vitro comparison provides biomechanical data on two PIP arthrodesis techniques, but clinical outcomes depend on factors beyond structural properties such as surgical technique, implant positioning, and biological healing
  • While mechanical testing is valuable for construct design, surgeon selection between these techniques should also consider clinical applicability, complication rates, and case-specific anatomy
  • Consider reviewing clinical follow-up studies and long-term outcomes for these techniques before changing surgical protocols, as in vitro strength does not always predict field performance
  • Acutrak-Plus screws perform equally to standard AO cortical screws for pastern fusion, offering surgeons an alternative fixation option with potentially different handling characteristics
  • Consider limb type when selecting fixation for PIP arthrodesis, as forelimbs demonstrate different biomechanical properties than hindlimbs
  • Both screw systems achieved adequate stiffness for arthrodesis; clinical choice can be based on surgeon preference, cost, and availability rather than biomechanical superiority
  • This in vitro study provides biomechanical data to inform surgical technique selection for PIP joint arthrodesis, but clinical outcomes must be verified in practice
  • Compare the mechanical properties of available fixation systems to optimize construct rigidity and durability for your cases
  • Consider that in vitro results may not fully predict in vivo performance due to biological factors and dynamic loading patterns
  • Either plating technique is biomechanically suitable for PIP arthrodesis; choice can be based on surgeon preference and anatomical considerations rather than structural superiority
  • The 5-hole 4.5-mm narrow DCP may offer practical advantages in ease of application, while the 7-hole 3.5-mm broad DCP provides greater versatility if fracture repair rather than arthrodesis is needed
  • Plate bending with subsequent screw head pullthrough is a potential failure mode; consider this in case selection and post-operative monitoring
  • Use two 5.5-mm screws instead of three 4.5-mm screws for pastern arthrodesis—it's simpler surgery with identical biomechanical strength
  • Front limbs tolerate higher loads than hind limbs in pastern arthrodesis, which may inform postoperative exercise recommendations
  • Larger diameter screws (5.5-mm) are more durable than smaller ones; consider this when selecting implants for demanding cases

Key Research Findings

For inexperienced surgeons, the 3D-printed aiming device reduced procedure time by 25% (27.24 to 20.16 min, p<0.01)

Aimonetti Emma, 2026

Device use decreased intraoperative radiographs by 60% for inexperienced surgeons (6.1 to 2.1 images, p<0.01)

Aimonetti Emma, 2026

Screw placement accuracy improved 31% for inexperienced surgeons with the device (4.4 to 5.8 score, p<0.01)

Aimonetti Emma, 2026

For experienced surgeons, only radiograph reduction was significant (58% decrease); no improvement in procedure time, accuracy or symmetry

Aimonetti Emma, 2026

CT imaging provided fracture configuration details not visible on radiographs in all 6 cases, enabling superior surgical planning

Marcatili Marco, 2025

CT identified concurrent pathology in 3 of 6 cases: navicular bone fractures (2 cases) and DDFT rupture (1 case)

Marcatili Marco, 2025

Four horses survived to >6 months follow-up with mild 3/5 AAEP lameness after internal fixation with dual dorsally-located plates

Marcatili Marco, 2025

CT-guided surgical planning improved construct stability through precise positioning of multiple cortical lag screws

Marcatili Marco, 2025

A yearling filly with a large clinically significant OCLL on the distal joint surface of the proximal phalanx was successfully treated with surgical arthrodesis of the proximal interphalangeal joint using three lag screws

Kol'vek Filip, 2021

Calcium phosphate biocement was used to pack the cyst cavity after curetting to encourage lesion filling

Kol'vek Filip, 2021

Surgical arthrodesis combined with biocement packing provided a treatment option for phalangeal cysts on the convex surface where conservative treatment presents technical challenges

Kol'vek Filip, 2021

PIP-LCP with abaxial transarticular lag screws is a viable surgical technique for PIPJ arthrodesis in horses

Hicks Rebecca B, 2021

Clinical outcomes following this technique are being documented to fill a gap in the literature regarding this specific fixation method

Hicks Rebecca B, 2021

74% of Warmbloods/Thoroughbreds and 87% of Quarter Horses achieved successful post-operative outcomes after PIP joint arthrodesis

Herthel T D, 2016

57% of Warmbloods/Thoroughbreds and 63% of Quarter Horses used for athletic performance returned to successful competition

Herthel T D, 2016

Evidence Base

3D printed aiming device for equine proximal interphalangeal joint arthrodesis: Ex vivo study.

Aimonetti Emma, Genton Martin, Lischer Christoph Johannes et al. (2026)Veterinary surgery : VS

Case Report

Use of preoperative computed tomography (CT) to plan repair of comminuted fractures of the middle phalanx in six Warmblood horses: Configuration, treatment and long-term outcome.

Marcatili Marco, Kalinovskiy Andrey, Christoph Lischer (2025)Veterinary surgery : VS

Case Report

Modified Proximal Interphalangeal Joint Arthrodesis in a Yearling Filly with an Osseous Cyst-Like Lesion in the Proximal Phalanx.

Kol'vek Filip, Kre&#x161;&#xe1;kov&#xe1; Lenka, Vdoviakov&#xe1; Katar&#xed;na et al. (2021)Animals : an open access journal from MDPI

Case Report

Proximal interphalangeal locking compression plate for pastern arthrodesis in horses.

Hicks Rebecca B, Glass Kati G, Watkins Jeffrey P (2021)Equine veterinary journal

Case Report

Retrospective analysis of factors associated with outcome of proximal interphalangeal joint arthrodesis in 82 horses including Warmblood and Thoroughbred sport horses and Quarter Horses (1992-2014).

Herthel T D, Rick M C, Judy C E et al. (2016)Equine veterinary journal

Case Report

Evaluation of ethyl alcohol for use in a minimally invasive technique for equine proximal interphalangeal joint arthrodesis.

Wolker Ryan R E, Wilson David G, Allen Andrew L et al. (2011)Veterinary surgery : VS

Case Report

Clinical use of the locking compression plate (LCP) in horses: a retrospective study of 31 cases (2004-2006).

Levine D G, Richardson D W (2007)Equine veterinary journal

Case Report

Arthrodesis of the equine proximal interphalangeal joint: a mechanical comparison of 2 parallel 5.5 mm cortical screws and 3 parallel 5.5 mm cortical screws.

Read Emma K, Chandler Diane, Wilson David G (2005)Veterinary surgery : VS

Case Report

Treatment of traumatic disruption of the suspensory apparatus in Thoroughbred racehorses at risk of proximal interphalangeal joint subluxation using a locking compression-distal femur plate for double arthrodesis.

Orozco Lopez David, Garcia-Lopez Jose M, Carpenter Ryan et al. (2025)Veterinary surgery : VS

Expert Opinion

Proximal interphalangeal joint arthrodesis in the horse

Heim C, Sommer K S, Fürst A (2021)Pferdeheilkunde Equine Medicine

Expert Opinion

In vitro biomechanical comparison of a 5-hole 4.5&#x2009;mm locking compression plate and 5-hole 4.5&#x2009;mm dynamic compression plate for equine proximal interphalangeal joint arthrodesis.

Seo Jong-Pil, Yamaga Takashi, Tsuzuki Nao et al. (2014)Veterinary surgery : VS

Expert Opinion

In vitro biomechanical comparison of a 4.5 mm narrow locking compression plate construct versus a 4.5 mm limited contact dynamic compression plate construct for arthrodesis of the equine proximal interphalangeal joint.

Ahern Benjamin J, Showalter Brent L, Elliott Dawn M et al. (2013)Veterinary surgery : VS

Expert Opinion

A mechanical comparison of equine proximal interphalangeal joint arthrodesis techniques: an axial locking compression plate and two abaxial transarticular cortical screws versus an axial dynamic compression plate and two abaxial transarticular cortical screws.

Sod Gary A, Riggs Laura M, Mitchell Colin F et al. (2011)Veterinary surgery : VS

Expert Opinion

Arthrodesis of the equine proximal interphalangeal joint: a biomechanical comparison of 3-hole 4.5 mm locking compression plate and 3-hole 4.5 mm narrow dynamic compression plate, with two transarticular 5.5 mm cortex screws.

Zoppa Andr&#xe9; L V, Santoni Brandon, Puttlitz Christian M et al. (2011)Veterinary surgery : VS

Expert Opinion

An in vitro biomechanical comparison of equine proximal interphalangeal joint arthrodesis techniques: two parallel transarticular headless tapered variable pitch screws versus two parallel transarticular AO cortical bone screws inserted in lag fashion.

Gudehus Timm, Sod Gary A, Riggs Laura M et al. (2011)Veterinary surgery : VS

Expert Opinion

An in vitro biomechanical comparison of equine proximal interphalangeal joint arthrodesis techniques: an axial positioned dynamic compression plate and two abaxial transarticular cortical screws inserted in lag fashion versus three parallel transarticular cortical screws inserted in lag fashion.

Sod Gary A, Riggs Laura M, Mitchell Colin F et al. (2010)Veterinary surgery : VS

Expert Opinion

Arthrodesis of the equine proximal interphalangeal joint: a biomechanical comparison of two parallel headless, tapered, variable-pitched, titanium compression screws and two parallel 5.5 mm stainless-steel cortical screws.

Wolker Ryan R E, Carmalt James L, Wilson David G (2009)Veterinary surgery : VS

Expert Opinion

In vitro biomechanical comparison of equine proximal interphalangeal joint arthrodesis techniques: prototype equine spoon plate versus axially positioned dynamic compression plate and two abaxial transarticular cortical screws inserted in lag fashion.

Sod Gary A, Mitchell Colin F, Hubert Jeremy D et al. (2007)Veterinary surgery : VS

Expert Opinion

Arthrodesis of the equine proximal interphalangeal joint: a biomechanical comparison of two 7-hole 3.5-mm broad and two 5-hole 4.5-mm narrow dynamic compression plates.

Watt Bruce C, Edwards Ryland B, Markel Mark D et al. (2002)Veterinary surgery : VS

Expert Opinion

Arthrodesis of the equine proximal interphalangeal joint: a biomechanical comparison of three 4.5-mm and two 5.5-mm cortical screws.

Watt B C, Edwards R B, Markel M D et al. (2001)Veterinary surgery : VS

Expert Opinion